• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.221-228
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• 2019

The effects of wind speed on the temperature change during day time could be insignificant in a region with a complex terrain. The objective of this study was to derive empirical relationship between solar radiation and hourly temperature under a windy condition for the period from sunrise to sunset in order to improve hourly air temperature at a site-specific scale. The deviation of the temperature measurements was analyzed along with the changes of the hourly sunlight at weather observation sites located on the east and west slopes under given wind speed. An empirical model where wind speed use used as an independent variable was obtained to quantify the solar effects on the temperature change (MJ/㎡). This model was verified estimating the hourly temperature during the daytime (0600-1900 h) at 25 weather observation sites located in the study area that has complex topography for the period from January to December 2018. The mean error (ME) and root mean square error (RMSE)of the estimated and measured values ranged from -0.98 to 0.67 ℃, and from 0.95 to 2.04 ℃, respectively. The daytime temperature at 1500 h were estimated using new and previous models. It was found that to the model proposed in the present study reduced the measurement errors of the hourly temperature in the afternoon in comparison with the previous model. For example, the ME and RMSE of the previous model were (ME -0.91 ℃ and 1.47 ℃, respectively. In contrast, the values of ME and RMSE were -0.45 ℃ and 1.22 ℃ for the new model, respectively. Our results suggested that the reliability of hourly temperature estimates at a specific site could be improved taking into account the effect of wind as well as solar radiation.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.229-235
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• 2005

A problem that affects children's dentitions is the harmful habit which is difficult to treat. Harmful habits for children are such as abnormal swallowing patterns, low/forward tongue rest posture problem, habitual open-lips resting posture, habitual mouth-breathing, excessive digital sucking habit and tongue thrusting. Tongue thrusting habits cause a bit of cranio-facial skeletal changes and a great deal of dental malocclusion such as anterior open bite. Anterior open bite causes masticatory, speech, and esthetic problems in the growing children and difficulties in diagnosis, treatment, and the prediction of its prognosis. The treatments of such abnormal behaviors involve orofacial myofunctional therapy and using of habit breaking appliance. The prognosis is not determined by the presence of severity of oral habit but the skeletal tendency of the patient. Usage of tongue crib resulted in not only the discontinuance of the habit but also improvement in overbite and overbite. This study showed that relatively successful results could be generated by using removable tongue crib and myofunctional therapy in the case of openbite related to tongue thrusting habit.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.1-10
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• 2011

Recently, cloud computing which has provided enabling convenience that users can connect from anywhere and user friendly environment that offers on-demand network access to a shared pool of configurable computing resources such as smart-phones, net-books and PDA etc, is to be watched as a service that leads the digital revolution. Now, when business practices between departments being integrated through a cooperating system such as cloud computing, data streaming between departments is getting enormous and then it is inevitably necessary to find the solution that person in charge and find data they need. In previous studies the clustering simplifies the search process, but in this paper, it applies Hash Function to remove the de-duplicates in large amount of data in business firms. Also, it applies Bayesian Network of data mining for classifying the respect data and presents handling cloud computing based data. This system features improved search performance as well as the results Compared with conventional methods and CPU, Network Bandwidth Usage in such an efficient system performance is achieved.

• Spatial Information Research
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• v.23 no.5
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• pp.53-64
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• 2015

Several countries have built National Spatial Data Infrastructure (NSDI) for information sharing among various fields. One of the important factors of NSDI is framework data, which is the most commonly used geospatial data across various fields. Previous studies on the framework data suggest components based on frequency survey and case study. However, such research methods do not have objectivity in setting the components of the framework data. This research uses factor analysis with 104 medium-level layers from the most widely used National Base Map and 5 layers from the other sources including cadastre and aerial image. Each layer is scaled with usage level as four different patterns of 1) background data, 2) reference data, 3) base data, and 4) other data, respectively. The analysis results show that the layers are grouped into 5 to 7 factors according to the patterns. ANOVA reveals that the mean differences between the factors with high values and the other factors with low values under each pattern are statistically significant. Such high value factors under each pattern consist of similar layers, close to identical, with those under the other categories. This research proposes framework data system, including transportation, building, hydrography, elevation, administrative district, digital orthoimagery, geodetic control, and cadastral based on the analysis results. Proposed framework in this research will be a basis of establishing spatial data sharing system. For sharing proposed framework data in various fields, these data must be established and distributed as actual standard and also related future researches should be performed.

• Management & Information Systems Review
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• v.31 no.3
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• pp.47-73
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• 2012

SNS allowed users to serve not only as the content and message producer but as the consumer, with development into various types of SNS platforms. Instead of a traditional media structure of media-to-many and unspecified users, it also made it possible to achieve one-to-one or one-to-many interactions, regardless of time and space, through SNS platforms. Moreover, according to development of digital communication technology, IT, media contents and communication network have been mutually connected, though they were once separate. The changes in communication environments have caused rapid disorganization and reorganization in popular culture led by specific expert groups. Such trend has a greater influence on marketing strategies of enterprises. In other words, it will lead them to mostly introduce new information technologies, based on consumer market, and to strategically participate in SNS for promotion and marketing for their products and brands. Likewise, SNS has currently appeared as the main media affecting consumers' behaviors. In consideration of the importance of SNS features, which can stimulate responses of other users, analysis of main features affecting SNS user acceptance decision is required, as well as its utilization strategies. Accordingly, this study conducted division of SNS features into openness, quickness, interactiveness and economical efficiency to derive strategies for increasing the usage frequency of SNS and ultimately maximizing the expectation effect, in addition to an empirical analysis of effects of SNS features on usefulness, easiness and pleasure perceived in SNS, and SNS user intention.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.3
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• pp.623-628
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• 2009

The emergence of compact and low-power wireless communication sensors and actuators in the technology supporting the ongoing miniaturization of processing and storage allows for entirely the new kinds of embedded systems. These systems are distributed and deployed in environments where they may have been designed into a particular control method, and are often very dynamic. Collection of devices can communicate to achieve a higher level of coordinated behavior. Wireless sensor nodes deposited in various places provide light, temperature, and activity measurements. Wireless sensor nodes attached to circuits or appliances sense the current or control the usage. Together they form a dynamic and multi-hop routing network connecting each node to more powerful networks and processing resources. Wireless sensor networks are a specific-application and therefore they have to involve both software and hardware. They also use protocols that relate to both applications and the wireless network. Wireless sensor networks are consumer devices supporting multimedia applications such as personal digital assistants, network computers, and mobile communication devices. Wireless sensor networks are becoming an important part of industrial and military applications. The characteristics of modem embedded systems are the capable of communicating adapting the different operating environments. In this paper, We designed and implemented sensor network system which shows through host PC sensing temperature and humidity data transmitted for wireless sensor nodes composed wireless temperature and humidity sensor and designs sensor nodes using embedded system with the intention of studying USN.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.1
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• pp.15-22
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• 2017

With the advance of Internet Technology, various social network services are created and used by users. Especially, the use of smart devices makes that multimedia contents can be used and distributed on social network services. However, since the crime rate also is increased by users with illegal purposes, there are needs to protect contents and block illegal usage of contents with multimedia forensics. In this paper, we propose a multimedia forensic technique which is identifying the video source. First, the scheme to acquire the sensor pattern noise (SPN) using morphology filtering is presented, which comes from the imperfection of photon detector. Using this scheme, the SPN of reference videos from the reference device is estimated and the SPN of an unknown video is estimated. Then, the similarity between two SPNs is measured to identify whether the unknown video is acquired using the reference device. For the performance analysis of the proposed technique, 30 devices including DSLR camera, compact camera, camcorder, action cam and smart phone are tested and quantitatively analyzed. Based on the results, the proposed technique can achieve the 96% accuracy in identification.

• Journal of Broadcast Engineering
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• v.9 no.4 s.25
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• pp.305-321
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• 2004

With the advent of the digital broadcasting, the audiences can access a large number of TV programs and their information through the multiple channels on various media devices. The access to a large number of TV programs can support a user for many chances with which he/she can sort and select the best one of them. However, the information overload on the user inevitably requires much effort with a lot of patience for finding his/her favorite programs. Therefore, it is useful to provide the persona1ized broadcasting service which assists the user to automatically find his/her favorite programs. As the growing requirements of the TV personalization, we introduce our automatic user preference learning algorithm which 1) analyzes a user's usage history on TV program contents: 2) extracts the user's watching pattern depending on a specific time and day and shows our automatic TV program recommendation system using MPEG-7 MDS (Multimedia Description Scheme: ISO/IEC 15938-5) and 3) automatically calculates the user's preference. For our experimental results, we have used TV audiences' watching history with the ages, genders and viewing times obtained from AC Nielson Korea. From our experimental results, we observed that our proposed algorithm of the automatic user preference learning algorithm based on the Bayesian network can effectively learn the user's preferences accordingly during the course of TV watching periods.

• Journal of Broadcast Engineering
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• v.6 no.3
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• pp.246-259
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• 2001

Due to recent rapid deployment of Internet streaming service and digital broadcasting service, the issue of how to efficiently support streaming workload in so called "Internet Home Appliance" receives prime interests from industry as well as academia. The underlying dilemma is that it may not be feasible to put cutting edge CPU, boards, disks and other peripherals into that type of device. The primary reason is its cost. Usually, Internet Home Appliances has its dedicated usage, e.g. Internet Radio, and thus it does not require high-end CPU nor high-end Va subsystem. The same reasoning applies to I/O subsystem. In Internet Home Appliances dedicated to handle compressed moving picture, it is not equipped with high end SCSI disk with fast rotational speed. Thus, it is mandatory to devise elaborate software algorithm to exploit the available hardware resources and maximize the efficiency of the system. This paper presents our experiences in the design and implementation of a new multimedia file system which can efficiently deliver the required disk bandwidth for a periodic I/O workload. We have implemented the file system on the Linux operating system, and examined itsperformance under streaming I/O workload. The results of the study show that the proposed file system exhibits superior performance than the Linux Ext2 file system under streaming I/O workload. The result of this work not only contribute to advance the state f art file system technology for multimedia streaming but also put forth the software which is readily available and can be deployed. deployed.

• KIISE Transactions on Computing Practices
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• v.22 no.8
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• pp.375-380
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• 2016

The proliferation of online social networking services (OSNSs) and smartphones has enabled people to easily make friends with a large number of users in the online communities, and interact with each other. This leads to an increase in the usage rate of OSNSs. However, individuals who have immersed into their digital lives, prioritizing the virtual world against the real one, become more and more isolated in the physical world. Thus, their socialization processes that are undertaken only through lots of face-to-face interactions and trial-and-errors are apt to be neglected via 'Add Friend' kind of functions in OSNSs. In this paper, we present a friend recommendation system based on the on/off-line contextual information for the OSNS users to have more serendipitous offline interactions. In order to accomplish this, we modeled both offline information (i.e., place visit history) collected from a user's smartphone on a 3D tensor, and online social data (i.e., friend relationships) from Facebook on a matrix. We then recommended like-minded people and encouraged their offline interactions. We evaluated the users' satisfaction based on a real-world dataset collected from 43 users (12 on-campus users and 31 users randomly selected from Facebook friends of on-campus users).