• KIPS Transactions on Computer and Communication Systems
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• v.6 no.2
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• pp.95-104
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• 2017

As the technology in smart device is growing and Social Network Services(SNS) are becoming more common, the data which is difficult to be processed by existing RDBMS are increasing. As a result of this, NoSQL databases are getting popular as an alternative for processing massive and unstructured data generated in real time. The demand for the technique of digital investigation of NoSQL databases is increasing as the businesses introducing NoSQL database in their system are increasing, although the technique of digital investigation of databases has been researched centered on RDMBS. New techniques of digital forensic investigation are needed as NoSQL Database has no schema to normalize and the storage method differs depending on the type of database and operation environment. Research on document-based database of NoSQL has been done but it is not applicable as itself to other types of NoSQL Database. Therefore, the way of operation and data model, grasp of operation environment, collection and analysis of artifacts and recovery technique of deleted data in HBase which is a NoSQL column-based database are presented in this paper. Also the proposed technique of digital forensic investigation to HBase is verified by an experimental scenario.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.483-488
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• 2015

This paper implements a long-term monitoring system (LMS) for ship's engine performance analysis (SEPA) based on the web, for the purpose of the communication speed and engine maintenance. This system is composed of a simulator, monitoring module with a multi channel A/D converter, monitoring computer, network attached storage (NAS), RS485 serial and wireless internet communication system. The existing products monitor the information transmitted from pressure sensors installed in the upper parts of each of engines in the local or web computer, but have a delay in the communication speed and errors in long-term monitoring due to the large volume of sampling pressure data. To improve these problems, the monitoring computer saves the sampling pressure data received from the pressure sensors in NAS, monitors the long-term sampling data generated by the sectional down sampling method on a local computer, and transmits them to the web for long-term monitoring. Because this method has one tenth of the original sampling data, it will use memory with small capacity, save communication cost, monitor the long-term sampling data for 30 days, and as a result, make a great contribution to engine maintenance.

• 대한공업교육학회지
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• v.32 no.1
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• pp.134-152
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• 2007

This study deals with the development of computer program which can restrict students to access to the unallowable web sites during the Internet based class. Our suggested program can find the student's access list to the unallowable sites, display it on the teacher's computer screen. Through the limitation of the student's access, teacher can enhance the efficiency of class and fulfill his educational purpose for the class. The use of our results leads to the effective and safe utilization of the Internet as the teaching tools in the class. Meanwhile, the typical method is to turn off the LAN (Local Area Network) power in order to limit the student's access to the unallowable web sites. Our program has been developed on the Linux operating systems in the small network environment. The program includes following five functions: the translation function to change the domain name into the IP(Internet Protocol) address, the search function to find the active students' computers, the packet snoop to capture the ongoing packets and investigate their contents, the comparison function to compare the captured packet contents with the predefined access restriction IP address list, and the restriction function to limit the network access when the destination IP address is equal to the IP address in the access restriction list. Our program can capture all passing packets through the computer laboratory in real time and exactly. In addition, it provides teacher's computer screen with the all relation information of students' access to the unallowable sites. Thus, teacher can limit the student's unallowable access immediately. The proposed program can be applied to the small network of the elementary, junior and senior high school. Our research results make a contribution toward the effective class management and the efficient computer laboratory management. The related researches provides teacher with the packet observation and the access limitation for only one host, but our suggested program provides teacher with those for all active hosts.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.475-480
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• 2005

인터넷상에 존재하는 수 많은 웹 페이지들에는 정형화되지 않은 각종 정보들이 이종의 형태로 산재되어 있다. 현재의 검색 기술을 통하여 필요한 정보를 찾아내는 것은 시간과 비용이 많이 소요되는 비효율적인 방법으로 이뤄지고 있다. 이러한 상황에서 사용자가 원하는 정보를 검색 및 추출해내어 정형화시키는 것은 매우 중요하다. 전자상거래의 폭발적 성장에도 불구하고 전자상거래 표준 활용 및 적용이 미비하여 e- Procurement, e-Marketplace, on-Line Shopping Mall 등에서 소비자가 원하는 상품 정보를 손쉽게 획득하지 못하고 있다. 이는 공급자에게는 보다 많은 매출의 기회를 구매자에게는 보다 좋은 자재 및 상품을 저렴한 가격에 소싱 할 수 있는 기회를 제공하지 못하는 문제점이 발생한다. 본 연구에서 제안하고자 하는 지능형 상품 에이전트는 소비자가 구매하고자 하는 특정 상품에 대한 공급자 검색 문제를 해결하기 위하여, 시스템 내부 정보의 확장 및 지식화 뿐만 아니라 웹 상의 다양한 상품 정보를 자동적으로 수집 및 가공하여 저장하는 역할을 수행한다. 이러한 연구를 위해서 사용한 기술은 우선 database 의 schema 를 읽어 들일 수 있는 DB schema reader, 인터넷 웹 페이지(웹문서)를 방문해서 다양한 정보들의 URL을 수집하는 일을 하는 Meta Search Engine 과 Focused Crawler, 그리고 다른 형태의 데이터 구조를 특정 목적에 따라 표준화된 형태로 바꾸는 Wrapper가 있다. 이러한 기술들을 연동하여 필요한 정보들을 추출 공급자 검색 문제를 해결하고자 하는 것이 연구의 목적이다. 정보추출은 사용자의 관심사에 적합한 문서들로부터 어떤 구체적인 사실이나 관계를 정확히 추출하는 작업을 가리킨다.앞으로 e-메일, 매신저, 전자결재, 지식관리시스템, 인터넷 방송 시스템의 기반 구조 역할을 할 수 있다. 현재 오픈웨어에 적용하기 위한 P2P 기반의 지능형 BPM(Business Process Management)에 관한 연구와 X인터넷 기술을 이용한 RIA (Rich Internet Application) 기반 웹인터페이스 연구를 진행하고 있다.태도와 유아의 창의성간에는 상관이 없는 것으로 나타났고, 일반 유아의 아버지 양육태도와 유아의 창의성간의 상관에서는 아버지 양육태도의 성취-비성취 요인에서와 창의성제목의 추상성요인에서 상관이 있는 것으로 나타났다. 따라서 창의성이 높은 아동의 아버지의 양육태도는 일반 유아의 아버지와 보다 더 애정적이며 자율성이 높지만 창의성이 높은 아동의 집단내에서 창의성에 특별한 영향을 더 미치는 아버지의 양육방식은 발견되지 않았다. 반면 일반 유아의 경우 아버지의 성취지향성이 낮을 때 자녀의 창의성을 향상시킬 수 있는 것으로 나타났다. 이상에서 자녀의 창의성을 향상시키는 중요한 양육차원은 애정성이나 비성취지향성으로 나타나고 있어 정서적인 측면의 지원인 것으로 밝혀졌다.징에서 나타나는 AD-SR맥락의 반성적 탐구가 자주 나타났다. 반성적 탐구 척도 두 그룹을 비교 했을 때 CON 상호작용의 특징이 낮게 나타나는 N그룹이 양적으로 그리고 내용적으로 더 의미 있는 반성적 탐구를 했다용을 지원하는 홈페이지를 만들어 자료 제공 사이트에 대한 메타 자료를 데이터베이스화했으며 이를 통해 학생들이 원하는 실시간 자료를 검색하여 찾을 수 있고 홈페이지를 방분했을 때 이해하기 어려운 그래프나 각 홈페이지가 제공하는 자료들에 대한 처리 방법을 도움말로 제공받을 수 있게 했다. 실시간 자료들을 이용한 학습은 학생들의 학습 의욕과 탐구 능력을 향상시켰으

• Smart Media Journal
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• v.11 no.3
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• pp.39-53
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• 2022

Cloud of Things (CoT) can provide IoT applications with unlimited storage functions and processing power supported by cloud services. However, in a centralized cloud of things, it can create a single point of failure that can lead to bottleneck problems, outages of the CoT network. In this paper, to solve the problem of centralized cloud of things and interoperate between different service domains, we propose an IoT service interoperability system using distributed fog computing and blockchain technology. Distributed fog is used to provide real-time data processing and services in fog systems located at a geographically close distance to IoT devices, and to enable service interoperability between each fog using smart contracts and distributed ledgers of the blockchain. The proposed system provides services within a region close to the distributed fog entrusted with the service from the cloud, and it is possible to access the services of other fogs without going through the cloud even between fogs. In addition, by sharing a service right token issuance information between the cloud and fog nodes using a blockchain network, the integrity of the token can be guaranteed and reliable service interoperability between fog nodes can be performed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.767-773
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• 2010

RFID and Kiosk has been acquiring the essential position not only for providing simple information but also as the tool for establishing Ubiquitous based society. Especially it can be said that the time for developing various Kiosks as important methods to conducting marketing and service through the differentiation and easiness on dealing information has come. Considering the present requirement, 'U-Commerce System' has been designed and developed. In the system, the RFID reader installed in 'U-Shop Kiosk System' recognizes the RFID tag on situated the specific products and detail product information and related multimedia advertisement are provided. Moreover, when the customers have the needs to purchase concerned products on the spot, they can pay and order by using credit cards. By employing the system, the amount of stock and delivery condition can be monitored in real time and the gathered information in DB can be used for dealing with stock related matters. In addition, a system can be developed to monitor and manage the remote shops in real time base. Furthermore, to overcome the limit of simple unmanned ubiquitous style Kiosk, the possibility of developing an expansion model of ubiquitous style CRM Kiosk has been suggested.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.2
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• pp.90-102
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• 2010

Flash memory has been widely used as an important storage device for consumer electronics. For the flash memory-based storage systems, FTL (Flash Translation Layer) is used to handle the mapping between a logical page address and a physical page address. Especially, log buffer-based FTLs provide a good performance with small-sized mapping information. In designing the log buffer-based FTL, one important factor is to determine the mapping structure between data blocks and log blocks, called associativity. While previous works use static associativity fixed at the design time, we propose a new log block mapping scheme which adjusts associativity based on the run-time workload. Our proposed scheme improves the I/O performance about 5~16% compared to the static scheme by adjusting the associativity to provide the best performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2235-2242
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• 2016

The electric power system based on fuel cell is applied in various forms to the ship and offshore plants. In particular, a research on the hybrid power system of the fuel cell combined with battery in connection topology has been researched actively. Fuel cell-based hybrid ship has not been carried out research, it is not carried out research in the integrated monitoring system. In this paper, we developed an integrated monitoring system to increase the convenience and stability for the hybrid fuel-cell ship operator. Research into integrated monitoring system based on GUI (Graphic User Interface), in consideration of the stability of the user convenience and ship operations, and developed communication and hardwired signal with the main equipment of the ship, to see in realtime state of the ship. The collected ship operation data is stored and it can be seen after the ship operating.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.30-41
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• 2006

This paper proposes an e-logistics system supporting efficient vehicle moving trajectory management. Recent advances in wireless communications have given rise to a number of location-based services including logistics vehicle tracking, cellular phone user's location finding, and location-based commerce. Logistics systems typically entail tracking vehicles for purposes of the logistics center knowing the whereabouts of the vehicles and/or consignments. Moreover, storing and managing location trajectory of continuously moving vehicles and consignments is necessary for supporting efficient logistics plan and consignment. The proposed system is able to manage spatial objects in GIS as well as logistic information in the mobile environment. And for the efficiently managing and retrieving of transporting trajectory of logistics, we extend previous moving object indexing method, TB-Tree, to use multi-version framework and evaluate data updating performance. It is able to apply the proposed method to develop mobile contents services based on continuously changing location of moving object in the mobile environment.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.909-914
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• 2011

In these days, according to the enhancement of the mobile communication technologies, location based services using the location and movements are vitalized. In this paper, we develop a private vehicle tracking system for garbage truck operation management using GPS and CDMA communication and Open map interface. The terminal equipment attached in vehicle receives the GPS signals and detect the position data including time, longitude, latitude, and altitude. And the terminal sends these data to the server PC through CDMA cellular network in fixed period. The server saves these data into database to process in map server program with which we can view real-time trace of moving vehicle. We apply our system to public garbage truck managing operation and we can increase operation efficiency by examine real-time working and moving path and by present reasonable operation rout.