• Journal of the Korea Society of Computer and Information
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• v.23 no.9
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• pp.65-71
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• 2018

Using mobile technology in educational and learning environments has attracted a lot of attention in recent years. In this mobile environment, mobile phones have been used to enhance the effectiveness of education in the field, which has been recognized through numerous experimental studies so far. The study was proposed and conducted to find out how much the use of mobile phones can have to improve the grammatical knowledge of EFL students. Introduction of 95 intermediate courses to Chungnam area The second grade students of 4-year college participated in this study. Everyone in the experimental and control groups was given the opportunity to review and recur to use the six grammar formats, including the current complete tense, simple past tense, direct and indirect question sentences, and comparative and superative-based methods. During the class discussion, the participants of the group record their voice on their cell phones, analyze the mistakes in the expressions recorded as a task after the class, and explain the results in the next session. However, in the class of the control group participants, this recording process is omitted. Participants benefited from mobile learning were much more positive in multidimensional grammar tests than those in control groups.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.4
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• pp.135-142
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• 2019

The objective of this study is to propose Korean Medicine treatment for recurrent limb weakness after Guillain-Barre syndrome (GBS) improvement by intraveinous immunoglobulin, and to report its effectiveness. Manual muscle test (MMT), Korean modified Bathel index (K-MBI), and tendon reflex were used to evaluate the patient. The patient was improved hip joint, knee joint, ankle joint MMT from grade 3-/3- to grade 5/5 and in the upper limb the patient can do big joint exercise but cannot do micromovement like writing or using cell phone. When discharge date the patient's wrist joint MMT grade is improved grade 5-/5- to grade 5/5. The K-MBI score is improved from 71 to 86 and there was a big change in walking and chair/bed transfer, there was no change in tendon reflex. This study suggests that Korean Medicine can be effective for patients who have recurrent limb weakness after GBS improvement.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.4
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• pp.1095-1109
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• 2022

Along with the popularity of GPS system and smart cell phone, trajectories of pedestrians or vehicles are recorded at any time. The great amount of works had been carried out in order to discover traffic paradigms or other regular patterns buried in the huge trajectory dataset. The core of the mining algorithm is how to evaluate the similarity, that is, the "distance", between trajectories appropriately, then the mining results will be accordance to the reality. Euclidean distance is commonly used in the lots of existed algorithms to measure the similarity, however, the trend of trajectories is usually ignored during the measurement. In this paper, a novel segment transform distance (STD) algorithm is proposed, in which a rule system of line segment transformation is established. The similarity of two-line segments is quantified by the cost of line segment transformation. Further, an improvement of STD, named ST-DTW, is advanced with the use of the traditional method dynamic time warping algorithm (DTW), accelerating the speed of calculating STD. The experimental results show that the error rate of ST-DTW algorithm is 53.97%, which is lower than that of the LCSS algorithm. Besides, all the weights of factors could be adjusted dynamically, making the algorithm suitable for various kinds of applications.

• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.547-554
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• 2022

Due to the expansion of non-face-to-face services, the demand for user identification for mobile devices is increasing. Recently, mobile resident registration cards, mobile driver's licenses, etc. are installed in mobile phones and used for user identification and authentication services. In order to identify a user online, unique identification information of the online user is required. In particular, in order to provide information only to online users, it is necessary to accurately deliver information to a mobile device owned by the user. To make this service possible, it was realized with the advent of mobile electronic notice service. However, the identification of online service users and information on mobile devices owned or subscribed by the relevant users require safe management as personal information, and it is also necessary to increase the convenience of online service users. In this paper, we propose an operating standard for providing a mobile electronic notice service that sends electronic notice using a mobile device owned by the user. The mobile electronic notice service is a service that provides notices expressed in electronic information to the recipient's cell phone, mobile app, e-mail, etc. Therefore, as the use of mobile electronic notification service increases and the provision and use of connecting information to identify users increases, it is necessary to expand the mobile electronic notification service while safely protecting users' personal information.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.83-89
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• 2022

For the purpose of promoting the excellence of Korea's unique traditional hanji around the world, it was intended to promote 'modernization of tradition' by producing and presenting cultural products suitable for modern sensibility using traditional hanji which is widely used in the arts. First of all, using hanji as a material, jumchi hanji was made by jumchi technique. Cut to a certain width according to the cultural products such as laptop case, cell phone case, hat, and bag. Weave the cut jumchi hanji with plaine weave, twill weave, and hexagon depending on the purpose of the cultural products to be made. A cultural products were made by matching the woven jumchi hanji with artificial leather, cotton, and denim.

• Korean Journal of Cognitive Science
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• v.33 no.1
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• pp.51-75
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• 2022

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation that is able to alter neuronal activity in particular brain regions. Many studies have researched how tDCS modulates neuronal activity and reorganizes neural networks. However it is difficult to conclude the effect of brain stimulation because the studies are heterogeneous with respect to the stimulation parameter as well as individual difference. It is not fully in agreement with the effects of brain stimulation. In particular few studies have researched the reason of variability of brain stimulation in response to time so far. The study investigated individual variability of brain stimulation based on circadian rhythm and chronotype. Participants were divided into two groups which are morning type and evening type. The experiment was conducted by Zoom meeting which is video meeting programs. Participants were sent experiment tool which are Muse(EEG device), tdcs device, cell phone and cell phone holder after manuals for experimental equipment were explained. Participants were required to make a phone in frount of a camera so that experimenter can monitor online EEG data. Two participants who was difficult to use experimental devices experimented in a laboratory setting where experimenter set up devices. For all participants the accuracy of 98% was achieved by SVM using leave one out cross validation in classification in the the effects of morning stimulation and the evening stimulation. For morning type, the accuracy of 92% and 96% was achieved in classification in the morning stimulation and the evening stimulation. For evening type, it was 94% accuracy in classification for the effect of brain stimulation in the morning and the evening. Feature importance was different both in classification in the morning stimulation and the evening stimulation for morning type and evening type. Results indicated that the effect of brain stimulation can be explained with brain state and trait. Our study results noted that the tDCS protocol for target state is manipulated by individual differences as well as target state.

• Journal of Mechanical Science and Technology
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• v.18 no.9
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• pp.1680-1688
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• 2004

The information indicating device plays an important part in the information times. Recently, the classical CRT (Cathod Ray Tube) display is getting transferred to the LCD (Liquid Crystal Display) one which is a kind of the FPDs (Flat Panel Displays). The OLED (Organic Light Emitting Diodes) display of the FPDs has many advantages for the low power consumption, the luminescence in itself, the light weight, the thin thickness, the wide view angle, the fast response and so on as compared with the LCD one. The OLED has lately attracted considerable attention as the next generation device for the information indicators. And also it has already been applied for the outside panel of a mobile phone, and its demand will be gradually increased in the various fields. It is manufactured by the vapor deposition method in the vacuum state, and the uniformity of thin film on the substrate depends on the temperature distribution in the point-cell source. This paper describes the basic concepts that are obtained to design the point-cell source using the computational temperature analysis. The grids are generated using the module of AUTOHEXA in the ICEM CFD program and the temperature distributions are numerically obtained using the STAR-CD program. The temperature profiles are calculated for four cases, i.e., the charge rate for the source in the crucible, the ratio of diameter to height of the crucible, the ratio of interval to height of the heating bands, and the geometry modification for the basic crucible. As a result, the blowout phenomenon can be shown when the charge rate for the source increases. The temperature variation in the radial direction is decreased as the ratio of diameter to height is decreased and it is suggested that the thin film thickness can be uniformed. In case of using one heating band, the blowout can be shown as the higher temperature distribution in the center part of the source, and the clogging can appear in the top end of the crucible in the lower temperature. The phenomena of both the blowout and the clogging in the modified crucible with the nozzle-diffuser can be prevented because the temperature in the upper part of the crucible is higher than that of other parts and the temperature variation in the radial direction becomes small.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.3
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• pp.142-149
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• 2005

To provide observed oceanography data at coastal fish and shellfish farm in the northeastern sea of the Korean peninsula on real time base, we developed real time application system for fisheries oceanography information. The system has been made up a mooring buoy system, a server for oceanography data collection, a server for archiving data and a database system, and a web server for providing fisheries oceanography information using internet. Futhermore, to support letters service on a cellular phone, we developed the communication system from mooring buoy to cell phone on real time base. The oceanography data derived from the system are water temperature speed and direction of current in surface layer middle layer and bottom layer in hour. We were able to quantify short term variation of ocean conditions within several days at shellfish farm such as a scallop sea farm using our system. To reduce damages of fish and shellfish farm from abnormal phenomena of ocean conditions such as a broken stratification of water, an occurrence of abnormal coastal cold water and warm water we will be able to move vertically and horizontally the sea farm facilities to proper conditions using real time oceanography information derive from the system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.209-220
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• 2013

Handover is the technology to minimize data lose of mobile devices and make continuous communication possible even if the device could be moved from one digital cell site to another one. That is, it is a function that enables the mobile user to avoid the disconnection of phone conversations when moving from a specific mobile communication area to another. Today, there are a lot of ongoing researches for fast and efficient hand-over, in order to address phone call's delay and disconnection which are believed to be the mobile network's biggest problems, and these should essentially be resolved in all mobile networks. Thanks to recent technology development in mobile network, the LTE network has been commercialized today and it has finally opened a new era that makes it possible for mobile phones to process data at high speed. In LTE network environment, however, a new authentication key must be generated for the hand-over. In this case, there can be a problem that the authentication process conducted by the hand-over incurs its authentication cost and delay time. This essay suggests an efficient key caching hand-over method which simplifies the authentication process: when UE makes hand-over from oMME to nMME, the oMME keeps the authentication key for a period of time, and if it returns to the previous MME within the key's lifetime, the saved key can be re-used.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.4
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• pp.827-839
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• 2012

A cell phone is very close to the user and therefore should be considered in digital forensic investigation. Recently, the proportion of smartphone owners is increasing dramatically. Unlike the feature phone, users can utilize various mobile application in smartphone because it has high-performance operating system (e.g., Android, iOS). As acquisition and analysis of user data in smartphone are more important in digital forensic purposes, smartphone forensics has been studied actively. There are two way to do smartphone forensics. The first way is to extract user's data using the backup and debugging function of smartphones. The second way is to get root permission, and acquire the image of flash memory. And then, it is possible to reconstruct the filesystem, such as YAFFS, EXT, RFS, HFS+ and analyze it. However, this methods are not suitable to recovery and analyze deleted data from smartphones. This paper introduces analysis techniques for fragmented flash memory pages in smartphones. Especially, this paper demonstrates analysis techniques on the image that reconstruction of filesystem is impossible because the spare area of flash memory pages does not exist and the pages in unallocated area of filesystem.