• Journal of Korean Tunnelling and Underground Space Association
• /
• v.25 no.3
• /
• pp.245-259
• /
• 2023

The purpose of this paper is to examine the most recent tunnel scanning systems to obtain insights for the development of non-contact mobile inspection system. Tunnel scanning systems are mostly being developed by adapting two main technologies, namely laser scanning and image scanning systems. Laser scanning system has the advantage of accurately recreating the geometric characteristics of tunnel linings from point cloud. On the other hand, image scanning system employs computer vision to effortlessly identify damage, such as fine cracks and leaks on the tunnel lining surface. The analysis suggests that image scanning system is more suitable for detecting damage on tunnel linings. A camera-based tunnel scanning system under development should include components such as lighting, data storage, power supply, and image-capturing controller synchronized with vehicle speed.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.31 no.6
• /
• pp.1157-1169
• /
• 2021

The disaster recovery refers to policies and procedures to ensure continuity of services and minimize loss of resources and finances in case of emergency situations such as natural disasters. In particular, the disaster recovery method by the cloud service provider has advantages such as management flexibility, high availability, and cost effectiveness. However, this method has a dependency on a service provider and has a structural limitation in which a user cannot be involved in personal data. In this paper, we propose a protocol using proxy re-encryption for data confidentiality by removing dependency on service providers by backing up user data using blockchain and distributed storage. The proposed method is implemented in Ethereum and IPFS environments, and presents the performance and cost required for backup and recovery operations.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.7
• /
• pp.2377-2398
• /
• 2021

In the recent modernized world, utilization of natural resources (renewable & non-renewable) is increasing drastically due to the sophisticated life style of the people. The over-consumption of non-renewable resources causes pollution which leads to global warming. Consequently, government agencies have been taking several initiatives to control the over-consumption of non-renewable natural resources and encourage the production of renewable energy resources. In this regard, we introduce an IoT powered integrated framework called as green home architecture (GHA) for green score calculation based on the usage of natural resources for household purpose. Green score is a credit point (i.e.,10 pts) of a family which can be calculated once in a month based on the utilization of energy, production of renewable energy and pollution caused. The green score can be improved by reducing the consumption of energy, generation of renewable energy and preventing the pollution. The main objective of GHA is to monitor the day-to-day usage of resources and calculate the green score using the proposed green score algorithm. This algorithm gives positive credits for economic consumption of resources and production of renewable energy and also it gives negative credits for pollution caused. Here, we recommend a green score based tax calculation system which gives tax exemption based on the green score value. This direct beneficiary model will appreciate and encourage the citizens to consume fewer natural resources and prevent pollution. Rather than simply giving subsidy, this proposed system allows monitoring the subsidy scheme periodically and encourages the proper working system with tax exemption rewards. Also, our GHA will be used to monitor all the household appliances, vehicles, wind mills, electricity meter, water re-treatment plant, pollution level to read the consumption/production in appropriate units by using the suitable sensors. These values will be stored in mass storage platform like cloud for the calculation of green score and also employed for billing purpose by the government agencies. This integrated platform can replace the manual billing and directly benefits the government.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.10
• /
• pp.5100-5119
• /
• 2018

Most of existing privacy-preserving multi-authorities attribute-based encryption schemes (PP-MA-ABE) only considers the privacy of the user identity (ID). However, in many occasions information leakage is caused by the disclosing of his/her some sensitive attributes. In this paper, we propose a collusion-resisting ciphertext-policy PP-MA-ABE (CRPP-MACP-ABE) scheme with hiding both user's ID and attributes in the cloud storage system. We present a method to depict anonymous users and introduce a managerial role denoted by IDM for the management of user's anonymous identity certificate ($AID_{Cred}$). The scheme uses $AID_{Cred}$ to realize privacy-preserving of the user, namely, by verifying which attribute authorities (AAs) obtain the blinded public attribute keys, pseudonyms involved in the $AID_{Cred}$ and then distributes corresponding private keys for the user. We use different pseudonyms of the user to resist the collusion attack launched by viciousAAs. In addition, we utilize IDM to cooperate with multiple authorities in producing consistent private key for the user to avoid the collusion attack launched by vicious users. The proposed CRPP-MACP-ABE scheme is proved secure. Some computation and communication costs in our scheme are finished in preparation phase (i.e. user registration). Compared with the existing schemes, our scheme is more efficient.

• Annual Conference of KIPS
• /
• 2013.11a
• /
• pp.835-838
• /
• 2013

클라우드 컴퓨팅을 사용하면 컴퓨팅 자원을 구축하는 비용을 절감할 수 있다는 장점이 있다. 문제는 클라이언트가 데이터 센터와 서비스제공자를 완전히 신뢰할 수 없다는 것이다. 예를 들어, 클라우드에 저장된 파일이 손실되었을 때 서비스 제공자는 서비스의 신뢰도가 떨어지는 것을 막기 위해 이를 숨길 수 있다. 이때, 데이터가 저장 후에 손실되었다는 것을 증명하지 못하면, 그 피해는 클라이언트에게 돌아오게 된다. 따라서, 클라이언트의 데이터를 보호하기 위하여 무결성을 검증할 수 있는 적절한 기법을 적용하여야 한다. 기존 연구로는 homomorphic tags 기반의 기법들이 많이 제안되었으나 이 기법은 많은 지수연산을 필요로 하므로 상용화할 수 있을 만큼의 효율성을 가지지 못한다. 특히, 클라이언트가 증거 생성을 위해 많은 연산을 부담해야 한다. 본 논문에서는 효율성에 중점을 둔, 특히 클라이언트의 효율성에 중점을 둔 무결성 검증 기법을 제안한다. 제안하는 기법은 Modular arithmetic을 기반으로 설계되었으며, 무결성 검증뿐만 아니라 데이터가 자주 업데이트 되는 환경을 지원한다. Simulation result는 제안하는 기법이 기존 기법에 매우 효율적임을 보여준다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.18 no.1
• /
• pp.149-156
• /
• 2023

This research tried to develop an ESS electricity trading system linked with blockchain for energy participation consumers. For the purpose of publishing renewable energy ESS power amount and demand information, we will build a smart contract system on the blockchain DB, utilize the blockchain DB data of energy prosumers and consumers, and expand the power trading market flexibly. to provide realistic solutions. Therefore, the main contents of the development of the ESS power trading system linked to the blockchain are cloud-based web construction for ESS management, coin issuance and exchange registration for activating the blockchain, and to reflect the blockchain technology, building a blockchain database for collecting and supplying ESS-based production demand data, selecting a blockchain-based platform and building a foundation, and creating a smart contract, etc.

• Journal of Korea Society of Industrial Information Systems
• /
• v.28 no.2
• /
• pp.47-60
• /
• 2023

This study proposed to adopt consortium blockchain for the database in the research support system of national R&D projects in order to increase efficiency, to reduce administrative burden, and to promote transparent research environment focusing on servicing researchers. Specifically, storage methods were classified according to data characteristics. First, data that requires integrity and transparency is stored in the blockchain, Second, confidentiality and data that require modification and deletion are stored in the database, Third, data that requires confidentiality, integrity, and transparency at the same time stores the original in the database, and the hash value of the data is separately stored in the blockchain. If research support system adopts blockchain, it is possible to operate the system stably, to share quick exchange of information between research institutes, to reduce administrative burden, to improve transparency of process, to resolve asymmetry of information, and to secure integrity, confidentiality, and availability of data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.39 no.6
• /
• pp.587-598
• /
• 2021

This study aims to develop a multi-camera based MMS (Mobile Mapping System) technology for building a HD (High Definition) map for autonomous driving and for quick update. To replace expensive lidar sensors and reduce long processing times, we intend to develop a low-cost and efficient MMS by applying multiple cameras and real-time data pre-processing. To this end, multi-camera storage technology development, multi-camera time synchronization technology development, and MMS prototype development were performed. We developed a storage module for real-time JPG compression of high-speed images acquired from multiple cameras, and developed an event signal and GNSS (Global Navigation Satellite System) time server-based synchronization method to record the exposure time multiple images taken in real time. And based on the requirements of each sector, MMS was designed and prototypes were produced. Finally, to verify the performance of the manufactured multi-camera-based MMS, data were acquired from an actual 1,000 km road and quantitative evaluation was performed. As a result of the evaluation, the time synchronization performance was less than 1/1000 second, and the position accuracy of the point cloud obtained through SFM (Structure from Motion) image processing was around 5 cm. Through the evaluation results, it was found that the multi-camera based MMS technology developed in this study showed the performance that satisfies the criteria for building a HD map.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.11
• /
• pp.1515-1527
• /
• 2016

With the growth of big data, machine learning, and cloud computing, the importance of storage that can store large amounts of unstructured data is growing recently. So the commodity hardware based distributed file systems such as MAHA-FS, GlusterFS, and Ceph file system have received a lot of attention because of their scale-out and low-cost property. For the data fault tolerance, most of these file systems uses replication in the beginning. But as storage size is growing to tens or hundreds of petabytes, the low space efficiency of the replication has been considered as a problem. This paper applied erasure coding data fault tolerance policy to MAHA-FS for high space efficiency and introduces VDelta technique to solve data consistency problem. In this paper, we compares the performance of two file systems, MAHA-FS and GlusterFS. They have different IO processing architecture, the former is server centric and the latter is client centric architecture. We found the erasure coding performance of MAHA-FS is better than GlusterFS.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.4
• /
• pp.117-123
• /
• 2013

In the recent cloud storage environment, the amount of SSD (Solid-State Drive) replacing with the traditional hard disk drive is increasing. Management of SSD for its space efficiency has become important since SSD provides fast IO performance due to no mechanical movement whereas it has wearable characteristics and does not provide in place update. In order to manage space efficiency of SSD, data de-duplication technique is frequently used. However, this technique occurs much overhead because it consists of data chunking, hasing and hash matching operations. In this paper, we propose new data de-duplication method using PRAM cache. The proposed method uses hierarchical hash tables and LRU(Least Recently Used) for data replacement in PRAM. First hash table in DRAM is used to store hash values of data cached in the PRAM and second hash table in PRAM is used to store hash values of data in SSD storage. The method also enhance data reliability against power failure by maintaining backup of first hash table into PRAM. Experimental results show that average writing frequency and operation time of the proposed method are 44.2% and 38.8% less than those of existing data de-depulication method, respectively, when three workloads are used.