• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.12
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• pp.2563-2567
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• 2011

Advances in smart sensors, embedded systems, low-power design, ad-hoc networks and MEMS have allowed the development of low-cost small sensor nodes with computation and wireless communication capabilities that can form distributed wireless sensor networks. Time information and time synchronization are fundamental building blocks in wireless sensor networks since many sensor network applications need time information for object tracking, consistent state updates, duplicate detection and temporal order delivery. Various time synchronization protocols have been proposed for sensor networks because of the characteristics of sensor networks which have limited computing power and resources. However, none of these protocols have been designed with time representation scheme in mind. Global time format such as UTC TOD (Universal Time Coordinated, Time Of Day) is very useful in sensor network applications. In this paper we propose network time protocol extension for global time presentation in wireless sensor networks.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.145-147
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• 2003

홈 제어 네트워크는 전력선으로 대표되는 물리적 네트워크를 기반으로 저속의 신뢰도 있는 통신을 한다. 현재 홈 제어 네트워크의 표준으로 거론되고 있는 것들은 CEBUS, EIB, LonWorks 등이 있다. 본 논문에서는 ETRI에서 작년에 개발한 론웍스(LonWorks) 시스템을 구성 관리하는 서버 소프트웨어인 LonWare(version 2.0)의 다중 바인딩을 지원하기 위한 연결(Connections) 구조를 제안한다. Echelon사에서 제안하는 LonWorks 시스템의 구성관리 도구로서의 LonMaker는 자체적으로 개발한 LNS (LonWorks Network Service)라고 하는 비 표준화된 구성 관리 기술을 통해서 네트워크를 관리하도록 지원하며, 상기한 LNS를 인프라로 활용하는 도구로서, LNS는 빌딩 혹은 가정 내에 LonWorks 네트워크로 연결되어 있는 디바이스들에 대한 정보를 DB화하여 구축된 자료를 기반 으로 디바이스들간에 연동이 가능하도록 지원한다. 그러나 고가이며, 바인딩 과정 시 론웍스 네트워크 상에 필요 이상의 패킷을 발생시켜 전력선 채널의 Bandwidth를 감소시키며, 또한 바이딩 과정을 마치는데 걸리는 시간을 증가시킨다. 이에 본 논문에서는 다중 바이딩을 지원하는 홈 네트워크 구성 관리 서버 소프트웨어의 연결 구조를 통해서 LonWare v2.0의 유니캐스트(unicast) 바이딩시 발생 했던 모든 문제를 제거하고, 바인딩에 필요한 패킷을 최적화 하여 바인딩에 걸리는 시간을 단축시키며, 성능의 주요한 요소인 디바이스의 리소스를 최소화하는 방법으로 접근하여 바인딩 시 처리능력의 한계를 가지고 있는 뉴런칩 기반의 론웍스 디바이스의 시스템 사양에 영향을 주지 않도록 제안하였다. 제안된 리눅스 기반의 홈 네트워크 구성 관리 소프트웨어의 다중 바인딩 기능을 통해 론웍스 네트워크상의 다양한 디바이스들간의 네트워크 다양화와 분산화 기능을 얻을 수 있었고, 기존의 고가의 해외 솔루션인 Echelon사의 LonMaker 소프트웨어를 사용하지 않고도 국내의 순수 솔루션인 리눅스 기반의 LonWare 3.0 다중 바인딩 기능을 통해 저 비용으로 홈 네트워크 구성 관리 서버 시스템 개발에 대한 비용을 줄일 수 있다.

• The Journal of the Korea Contents Association
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• v.11 no.6
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• pp.1-7
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• 2011

The methodology of KOSPI forecast has been considered as one of the most difficult problem to develop accurately since short-term KOSPI is correlated with various factors including politics and economics. In this paper, we presents a methodology for forecasting short-term trends of stock price for five days using the feature selection method based on a neural network with weighted fuzzy membership functions (NEWFM). The distributed non-overlap area measurement method selects the minimized number of input features by removing the worst input features one by one. A technical indicator are selected for preprocessing KOSPI data in the first step. In the second step, thirty-nine numbers of input features are produced by wavelet transforms. Twelve numbers of input features are selected as the minimized numbers of input features from thirty-nine numbers of input features using the non-overlap area distribution measurement method. The proposed method shows that sensitivity, specificity, and accuracy rates are 72.79%, 74.76%, and 73.84%, respectively.

• The Journal of the Korea Contents Association
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• v.8 no.7
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• pp.85-92
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• 2008

Meshes are the most appropriate data structures for representing 3D geometries. Surface meshes have been frequently used for representing 3D geometries, which only samples data on the surfaces of the given 3D geometries. Thanks to the improvements of computing powers, it is required to develop more complicated contents which utilize the volumetric information of 3D geometries. In this paper, we introduce a novel volumetric mesh libraries based on the half-face data structure, called OpenVolMesh, and describe its designs and implementations. The OpenVolMesh extends the OpenMesh, which is one of the most famous mesh libraries, by supporting volumetric meshes. The OpenVolMesh provides the generic programming, dynamic allocations of primitive properties, efficient array-based data structures, and source-level compatibility with OpenMesh. We show the usefulness of the OpenVolMesh in the developments of 3D volumetric contents with prototypic implementations such as volumetric mesh smoothing and CW-cell decompositions.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.8-17
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• 2014

Petascale systems(so called supercomputers) have been mainly used for supporting communication-intensive and tightly-coupled parallel computations based on message passing interfaces such as MPI(HPC: High-Performance Computing). On the other hand, computing paradigms such as High-Throughput Computing(HTC) mainly target compute-intensive (relatively low I/O requirements) applications consisting of many loosely-coupled tasks(there is no communication needed between them). In Korea, recently emerging applications from various scientific fields such as pharmaceutical domain, high-energy physics, and nuclear physics require a very large amount of computing power that cannot be supported by a single type of computing resources. In this paper, we present our HTCaaS(High-Throughput Computing as a Service) which can leverage national distributed computing resources in Korea to support these challenging HTC applications and describe the details of our system architecture, job execution scenario and case studies of various scientific applications.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.1
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• pp.33-37
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• 2011

In the fields of display, optics, and energy, it is important to improve micropattern-machining technology for achieving small patterns, large surface areas, and low cost. Unlike flat molds, roll molds have the following advantages: they can be manufactured within a short time, larger surface areas can be obtained, and continuous molding can be achieved. In this study, we aim to investigate the causes for errors in the shapes for a micropattern-machining process, and we show that by compensating the dynamic balance of roll molds, the dimensional accuracy of machined parts can be improved. The experimental results show that dynamic-balance compensation for a roll mold reduced the mass unbalance and the vibrations of the roll mold, and as a result, the dimensional accuracy of machined micropatterns has been improved.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.95-107
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• 2017

Since disasters have been getting stronger and wider according to the influence of climate change, those impacts on social and national economy have been also getting more severe in various subjects. However, as direct property damage as well as casualties are only measured in case of disasters, monetary figures on its losses are likely to be underestimated, which are known as a major barrier to both compensation for loss and making a regional disaster management plan. Thus, the main purpose of this study is to develop statistics appropriate to the direct and indirect socioeconomic losses, which have continuously been overlooked. To achieve this purpose, this study defines the scope of direct and indirect socioeconomic losses, provides a framework for developing those measurements, and determines a preliminary statistics list. Selection criteria to set the final list are decided and are then applied to the list. The result of this study can be used as basic data for further studies to estimate and calculate its socioeconomic losses from storm and flood.

• The Journal of the Korea Contents Association
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• v.17 no.2
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• pp.308-315
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• 2017

This study aims to review the differences and distinctive characteristics between storytelling method of virtual reality contents and storytelling method of conventional contents instead of focusing on economic and industrial effects of virtual reality contents. As a specific target, this study discusses how existing storytelling method of webtoons as a single contents genre can be applied to virtual reality contents when webtoons are adapted into virtual reality contents. The purpose of this study is to find limitations and possibilities for the storytelling technique of virtual reality contents. The results of this study showed that the essence of storytelling in virtual reality contents is in three roles of the users of virtual reality. The users of virtual reality must play the roles of service user, audience of contents, and director of story. This is because the most important storytelling techniques in media contents like editing and change of camera viewpoint can no longer be forced in virtual reality contents. Storytelling techniques in virtual reality contents are much limited compared to the conventional contents in terms of user interaction, expansion of senses, and guarantee of freedom.

• Journal of the Korean Society for information Management
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• v.20 no.3
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• pp.241-259
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• 2003

The Basic Semantic Register(BSR) is and official ISO register designed for interoperability among eBusiness and EDI systems. The entities registered in the current BSR are not defined in a machine-understandable way, which renders automatic extraction of structural and relationship information from the register impossible. The purpose of this study is to offer a framework for designing an ontology that can provide semantic interoperability among BSR-based systems by defining data structures and relationships with RDF and OWL, similar meaning by the 'equivalentClass' construct in OWL, the hierachical relationships among classes by the 'subClassOf' construct in RDF schema, definition of any entities in BSR by the 'label' construct in RDF schema, specification of usage guidelines by the 'comment' construct in RDF schema, assignment of classes to BSU's by the 'domain' construct in RDF schema, specification of data types of BSU's by the 'range' construct in RDF schema. Hierarchical relationships among properties in BSR can be expressed using the 'subPropertyOf' in RDF schema. Progress in semantic interoperability can be expected among BSR-based systems through applications of semantic web technology suggested in this study.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.3
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• pp.265-273
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• 2006

In the decommissioning and decontamination(D&D) planning stage, it is important that the scenarios are evaluated from an engineering point of views because the decommissioning work has to be executed economically and safely by following the best scenarios. Therefore, we need to develope several modules to evaluate the decommissioning scenarios. In this paper, the digital mock-up system is constructed in the virtual space to simulate the whole decommissioning process. The schedule evaluating equation and cost evaluation equation are derived to calculate the working time and the expected cost. And in order to easily identify the radiation level about the activated objects, the radiation visualization module is developed. Finally, on the basis of the obtained results from the Digital Mock-up and other important factors, the evaluating method of the scenarios that can indicate the best scenario is described.