• Journal of the Korean School Mathematics Society
• /
• v.18 no.1
• /
• pp.39-60
• /
• 2015

It is one of the fundamental issues that students in teaching and learning process should take a proactive role in school mathematics. Inquiry or discovery learning in school mathematics is the specific method for students to participate in lessons on their own initiative, which is supported by many scholars in mathematics education. In this paper, we investigate pre-service teachers' perspectives of Inquiry or discovery learning by intensively analyzing information and guided orientation in teaching practice. From this, we find the direction of the pre-service teacher training program for carrying out pre-service teachers' role to help students to take a proactive role in school mathematics.

• Journal of the Korea Convergence Society
• /
• v.12 no.5
• /
• pp.9-16
• /
• 2021

Due to the prolonged infectious disease of COVID-19 worldwide, there are various security threats due to network attacks on Internet of Things devices that are vulnerable to telecommuting. Initially, users of Internet of Things devices were exploited for vulnerabilities in Remote Desktop Protocol, spear phishing and APT attacks. Since then, the technology of network attacks has gradually evolved, exploiting the simple service discovery protocol of Internet of Things devices, and DRDoS attacks have continued to increase. Existing SSDPs are accessible to unauthorized devices on the network, resulting in problems with information disclosure and amplification attacks on SSDP servers. To compensate for the problem with the authentication procedure of existing SSDPs, we propose a hash-based SSDP that encrypts server-specific information with hash and adds authentication fields to both Notify and M-Search message packets to determine whether an authorized IoT device is present.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.05a
• /
• pp.108-110
• /
• 2021

Since 2015, attacks using the IoT protocol have been continuously reported. Among various IoT protocols, attackers attempt DDoS attacks using SSDP(Simple Service Discovery Protocol), and as statistics of cyber shelters, Korea has about 1 million open SSDP servers. Vulnerable SSDP servers connected to the Internet can generate more than 50Gb of traffic and the risk of attack increases gradually. Until recently, distributed denial of service attacks and distributed reflective denial of service attacks have been a security issue. Accordingly, the purpose of this study is to analyze the request packet of the existing SSDP protocol to identify an amplification attack and to avoid a response when an amplification attack is suspected, thereby preventing network load due to the occurrence of a large number of response packets due to the role of traffic reflection amplification.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.451-453
• /
• 2010

The world is rapidly evolving in the future society is based on intelligence. In such circumstances, USN(Ubiquitous Sensor Network) to implement the future ubiquitous(Ubiquitous) society have been highlighted as a key infrastructure. For realization of Ubiquitous computing(Ubiquitous Computing), The data recognized from each sensors must be collected on real-time and transferred to applied service so that they may be used as data for providing service to users. USN sensor data on the use for using a numerous sensor data provision service, service provider can publish its service in standardized registry for users to search and use the service registry. However, in previous studies using Web services standards WS-Eventing, and UDDI(Universal Description, Discovery, and Integration) as USR(USN Service Registry) for USN Application Service is unnecessary or insufficient. In this paper, data from sensors that provide information to service providers register their services and use the information for service users to explore and views on the registry of the system was designed and implemented.

• Proceedings of the IEEK Conference
• /
• 2004.08c
• /
• pp.558-561
• /
• 2004

Currently, most IP multicasting applications are implemented based on Any-Source Multicast (ASM) model that supports many to many multicast services. However, it is known that current ASM-based multicast architecture has several deployment problems such as address allocation, lack of access control, and inefficient handling of well-known multicast sources. Source-Specific Multicast (SSM) working group in IETF proposed SSM architecture to overcome the weaknesses of ASM architecture. The architecture of SSM is based on one to many multicast services. Also, in order to provide SSM service, Multicast Listener Discovery Version 2 (MLDv2) protocol should be supported. In this paper, we introduce the architecture of SSM protocol and multicast group management protocol. After that, we present the architecture and implementation of IPv6 SSM and MLDv2 protocols in Linux systems.

• Journal of Information Technology Services
• /
• v.10 no.2
• /
• pp.95-117
• /
• 2011

Today, IT governance has also become a subject of attention along with recent technologies such as ITSM (IT Service Management), PPM (Project Portfolio Management) and Compliance. At the national level, the market is fairly recent. and therefore, lacks detailed research in the field. Models specifically related to EIM has not yet been presented to this day, hence, firms that are considering EIM as a potential part of their information management system may fall into a state of disorder in the process of its implementation. To this end, this research attempts to construct an IT governance model for EIM based on existing models, surveys and interviews. In particular, E-discovery has been applied as means of protecting information assets and its use as evidence. In addition, by applying the research model to a particular global firm and then assessing its documentation management system, the overall feasibility of the research model has been tested.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.5
• /
• pp.1662-1681
• /
• 2015

The efficient send and receive of information in VANET improves the efficiency of the safety and traffic services advertisment and discovery. However, if the V2V is the only communication system used, the restrictions of the urban environment and network drop the performance of VANET. In order to improve the performance of the network, it is necessary to use V2I communication as well as V2V communication. Therefore, RSUs must be placed in the environment. However due to the high costs of placement, the full coverage of the environment would not be possible. Therefore, it is necessary to optimally install a limited number of RSUs in the environment.

• Journal of Information Technology Applications and Management
• /
• v.13 no.4
• /
• pp.121-140
• /
• 2006

UDDI (Universal Discovery Description and Integration) Registry is used for Web Services registration and search. UDDI offers the search result to the keyword-based query. UDDI supports WSDL registration but it does not supports WSDL search. So it is required that contents based search and ranking using name and description in UDDI registration information and WSDL. This paper proposes a retrieval engine considering contents of services registered in the UDDI and WSDL. It uses Vector Space Model for similarity comparison between contents of those. UDDI registry information hierarchy and WSDL hierarchy are considered during searching process. This engine suppports two discovery methods. One is Keyword-based search and the other is template-based search supporting ranking for user's query. Template-based search offers how service interfaces correspond to the query for WSDL documents. Proposed retrieval engine can offer search result more accurately than one which UDDI offers and it can retrieve WSDL which is registered in UDDI in detail.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.11a
• /
• pp.728-731
• /
• 2012

최근 분산 임베디드 시스템에서 실시간 데이터 교환에 대한 요구가 증가하면서 발간/구독(Publish/Subscribe) 기반의 데이터 중심 통신 미들웨어인 DDS(Data Distribution Service)에 대한 활용 분야가 증가하고 있다. 국방 분야의 시스템과 같은 고신뢰성을 요구하는 환경에서는 시스템 개발에 앞서, DDS 통신에 동적으로 참여하게 하는 디스커버리 과정의 안정적인 성능 검증을 요구한다. 성능 검증 및 신뢰성 있는 시스템 개발을 위해 실제 시스템과 유사한 환경에서 DDS의 디스커버리 사전시험(Prototype)을 수행하는 데, 이 때 많은 시간과 비용을 소요하게 된다. 본 논문에서는 DDS의 표준 프로토콜인 RTPS(Real-Time Publish-Subscribe)에서 필수로 요구하는 SDP(Simple Discovery Protocol)를 이용하여 디스커버리 시간을 추정할 수 있는 계산식을 제안한다. 계산식은 참여자(Participant) 수를 이용한 연결 쌍(pair)의 수식과 단말개체(Endpoints) 수를 이용한 가중치(weight) 수식을 이용하며, 실제 상용 DDS 미들웨어를 이용하여 유형별로 DDS 디스커버리 시험을 수행한 결과와 비교하여 계산식을 실제로 사용할 수 있음을 보인다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.05a
• /
• pp.363-366
• /
• 2014

OMG 그룹에서 제안하고 있는 DDS(Data Distribution Service) 미들웨어에서 디스커버리 프로토콜은 미들웨어 간의 상호 운용성 지원을 위한 기본 요소이다. DDS 미들웨어가 적용되는 대부분의 환경에서는 다수의 노드에서 생성된 참여자를 찾기 위해 한꺼번에 많은 수의 디스커버리 정보가 교환되기 때문에 노드 및 네트워크의 성능에 많은 영향을 미친다. 본 논문에서는 DDS 미들웨어 개발 후에 시험이 되어야 하는 디스커버리 기능의 검증과 성능 측정을 위한 응용을 설계하고 이를 구현하였다. 디스커버리 시험 응용은 디스커버리 시험 전체를 관리하는 제어 응용, DDS 미들웨어를 통하여 DDS 개체를 생성하고 이들간의 정보교환을 담당하는 DDS 응용, 그리고 DDS 응용을 통제하고 실행 결과를 수집하여 제어 응용으로 전송하는 데몬 서버로 구성된다. 구현된 디스커버리 시험 응용은 디스커버리 기능 검증 및 성능 정보의 수집을 프로세서 간의 통신을 통하여 효과적으로 수행한다. 또한, DDS 응용의 동작 권한을 제어 응용이 위치한 노드에 집중시킴으로써 많은 수의 노드에서 시험이 필요한 환경에 적합하도록 설계되었다.