• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.57-66
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• 2010

CAS Client personalization means to issue CAS ID or Key for CAS service, which is Core Technology for CAS operation. Protocol A.1 on TTA.KR-07.0079 XCAS, stores CAS Client personalization data from CAS server in XCAS server, and transmits the personalization data by request of XCAS HOST for CAS Client personalization. However, this may increase Network Traffic and CAS Client image management in XCAS server. In this thesis, to complement this, CAS Client personalization is executed on CAS Server by separating CAS service field. Therefore this can distribute Image management and Network Traffic of XCAS server.

• The Journal of Korean Association of Computer Education
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• v.15 no.6
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• pp.33-41
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• 2012

This paper presents the online assessment questions management system and method. The proposed system consists of a database to store learner information and zone-specific items grouped by difficulty and item bank. This database includes: an item selection department and authoring assessment to select questions about a particular learner or specific learning item. In this paper, we propose: an item bank database which stores online output assessments; and an online test department to collect and sort learner evaluation data and answer selection order for online tests, click statistics, response time, and analysis unit response patterns department by analyzing the data collected by the online learners' test assessment, learners' level and ability, the diagnosis and assessment of report propensity. The proposed system will diagnose and effectively evaluate the learner's learning levels and learning ability by: answer selection order, number of clicks, and response time reflected in the results of the learners' evaluations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.925-938
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• 2010

Depending on network conditions, a communication network could be overloaded when media are transmitted. Research has been carried out to lessen network overloading, such as by filtering, load distribution, frame dropping, and other methods. Among these methods, one of the most effective is frame dropping, which reduces specified video frames for bandwidth diminution. In frame dropping, B-frames are dropped and then I- and P-frames are dropped, based on the dependency among the frames. This paper proposes a scheme for protecting copyrights by encryption, when frame dropping is applied to reduce the bandwidth of media based on the MPEG-4 file format. We designed two kinds of frame dropping: the first stores and then sends the dropped files and the other drops frames in real time when transmitting. We designed three kinds of encryption methods using the DES algorithm to encrypt MPEG-4 data: macro block encryption in I-VOP, macro block and motion vector encryption in P-VOP, and macro block and motion vector encryption in I-, P-VOP. Based on these three methods, we implemented a digital rights management solution for MPEG-4 data streaming. We compared the results of dropping, encryption, decryption, and the quality of the video sequences to select an optimal method, and found that there was no noticeable difference between the video sequences recovered after frame dropping and the ones recovered without frame dropping. The best performance in the encryption and decryption of frames was obtained when we applied the macro block and motion vector encryption in I-, P-VOP.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.5842-5861
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• 2019

A current autonomous vehicle determines its driving strategy by considering only external factors (Pedestrians, road conditions, etc.) without considering the interior condition of the vehicle. To solve the problem, this paper proposes "An Optimal Driving Support Strategy(ODSS) based on an Genetic Algorithm for Autonomous Vehicles" which determines the optimal strategy of an autonomous vehicle by analyzing not only the external factors, but also the internal factors of the vehicle(consumable conditions, RPM levels etc.). The proposed ODSS consists of 4 modules. The first module is a Data Communication Module (DCM) which converts CAN, FlexRay, and HSCAN messages of vehicles into WAVE messages and sends the converted messages to the Cloud and receives the analyzed result from the Cloud using V2X. The second module is a Data Management Module (DMM) that classifies the converted WAVE messages and stores the classified messages in a road state table, a sensor message table, and a vehicle state table. The third module is a Data Analysis Module (DAM) which learns a genetic algorithm using sensor data from vehicles stored in the cloud and determines the optimal driving strategy of an autonomous vehicle. The fourth module is a Data Visualization Module (DVM) which displays the optimal driving strategy and the current driving conditions on a vehicle monitor. This paper compared the DCM with existing vehicle gateways and the DAM with the MLP and RF neural network models to validate the ODSS. In the experiment, the DCM improved a loss rate approximately by 5%, compared with existing vehicle gateways. In addition, because the DAM improved computation time by 40% and 20% separately, compared with the MLP and RF, it determined RPM, speed, steering angle and lane changes faster than them.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.7
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• pp.898-903
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• 2020

In this paper, we propose an indoor logistic tracking system that identifies the location and inventory of the logistics in the room based on fingerprints. Through this, we constructed the actual infrastructure of the logistics center and designed and implemented the logistics management system. The proposed system collects the signal strength through the location terminal and generates the signal map to locate the goods. The location terminal is composed of a UHF RFID reader and a wireless LAN card, reads the peripheral RFID signal and the signal of the wireless AP, and transmits it to the web server. The web server processes the signal received from the location terminal and stores it in the database, and the user uses the data to produce the signal map. The proposed system combines UHF RFID with existing fingerprinting method to improve performance in the environment of querying multiple objects.

• The Journal of Engineering Research
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• v.3 no.1
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• pp.107-116
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• 1998

Video data are retrieved and stored in various compressed forms according to their characteristics. In this paper, we present a generic data model that captures the structure of a video document and that provides a means for indexing a video stream. Using this model, we design and implement CVIMS (the MPEG-2 Compressed Video Information Management System) to store and retrieve video documents. CVIMS extracts I-frames from MPEG-2 TS files, selects key-frames from the I-frames, and stores in database the index information such as thumbnails, captions, and picture descriptors of the key-frames. And, CVIMS retrieves MPEG-2 video data using the thumbnails of key-frames and various labels of queries. And also, the system is accessible by a web interface.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.71-78
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• 2015

Since most education organizations such as Universities have a plenty of PCs, much electric power can be wasted if their power states are not managed properly. This paper introduces the RPM(Remote Power Management) software system implemented to reduce a waste of PC power in Universities. The System manager can monitor power state of all PCs in a University and turn off PCs or change power states of PCs to low power states. The RPM consists of three software modules. First, Power Controller, which is installed in each user PC, saves the power by changing low power state by utilizing low power algorithm proposed in this paper. Also it reports power state of its PC to Power Server on the state changed. Second, Power Server module gathers power state information of all PCs, stores them in a DB, and sends all or some parts of the information to Power Viewer whenever the manager asks. The manager can turn off or change a certain PC to low power state. We evaluated the performance of power saving for the RPM and the result showed achievement of 40% power saving.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.7-12
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• 2016

DRAM is commonly used as a smartphone memory medium, but extending its capacity is challenging due to DRAM's large battery consumption and density limit. Meanwhile, smartphone applications such as social network services need increasingly large memory, resulting in long latency due to additional storage accesses. To alleviate this situation, we adopt emerging nonvolatile memory (NVRAM) as smartphone's buffer cache and propose an efficient management scheme. The proposed scheme stores all dirty data in NVRAM, thereby reducing the number of storage accesses. Moreover, it separately exploits read and write histories of data accesses, leading to more efficient management of volatile and nonvolatile buffer caches, respectively. Trace-driven simulations show that the proposed scheme improves I/O performances significantly.

• Journal of the Korean Data and Information Science Society
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• v.23 no.1
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• pp.171-177
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• 2012

Various phenomenon can be expressed numerically and collected as a data due to rapid development of the computer. In particular large set of data is collected in various fields. We can obtain the information for final decision based on analysis and interpretation of the data. The issue is the management of the data as well as the importance of the data. So a system which stores the data in server and prints out the data to web browser is demanded. We uploaded the file of Excel form to server database and developed a web based program which can show the uploaded data through web based database. We used the Oracle DB for uploading and web programming language such as html, JAVA, JSP for querying the data. Finally, we developed a program for web based clinical data management system construction.

• Journal of the Korea Society of Computer and Information
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• v.18 no.12
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• pp.1-9
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• 2013

Even though the multiple pages TLB are effective in improving the performance, a conventional method with OS support cannot utilize multiple page sizes in user application. Thus, we propose a new multiple-TLB structure supporting multiple page sizes for high performance and low power consumption without any operating system support. The proposed TLB is organised as two parts of a S-TLB(Small TLB) with a small page size and a L-TLB(Large TLB) with a large page size. Both are designed as fully associative bank structures. The S-TLB stores small pages are evicted from the L-TLB, and the L-TLB stores large pages including a small page generated by the CPU. Each one bank module of S-TLB and L-TLB can be selectively accessed base on particular one and two bits of the virtual address generated from CPU, respectively. Energy savings are achieved by reducing the number of entries accessed at a time. Also, this paper proposed the simple 1-bit LRU policy to improve the performance. The proposed LRU policy can present recently referenced block by using an additional one bit of each entry on TLBs. This method can simply select a least recently used page from the L-TLB. According to the simulation results, the proposed TLB can reduce Energy * Delay by about 76%, 57%, and 6% compared with a fully associative TLB, a ARM TLB, and a Dual TLB, respectively.