• Journal of Digital Contents Society
• /
• v.14 no.1
• /
• pp.25-33
• /
• 2013

P2P(Peer-to-Peer) architecture can reduce the network bandwidth and resource on the server since peers exchange data chunks with each other, while server-client architecture causes a lot of traffic on the server. Peers receive a data more reliably when the number of participating peer increases. Currently, P2P traffic has accounted for about 65% of the world's Internet traffic and diverse P2P streaming services have launched combining to video streaming technology. However, the requirements and data chunk delivery algorithms for mobile P2P streaming service should be investigated, since the existing P2P technologies have been developed and designed for the wired network. In particular, the bandwidth fluctuation caused by user mobility, wireless packet collisions, and packet losses brings about different problems on the mobile P2P streaming service compared to existing P2P streaming service. In this paper, we analyzed the problem of mobile P2P streaming services in the 802.11n wireless LAN environment through experiments.

• Journal of Digital Convergence
• /
• v.15 no.7
• /
• pp.383-391
• /
• 2017

The purpose of this study was to examine users' attitude toward likability, understanding level, reliability, satisfaction, and continuous usage intention depending on a difference in a type between card news and straight news. A questionnaire survey was conducted targeting 232 people. As a result of the research, compared to the straight news, the card news was easy for a user to understand, was strong even in a desire to use continuously. Second, a factor of users' attitude toward news was having influence upon the mutually positive(+) direction. Likability, understanding level and reliability had an effect on satisfaction. The satisfaction had an impact again on continuous usage intention. The intensity of this impact was varied, respectively, in card news and straight news. The influential level upon satisfaction in card news was strong in order of likability, understanding level and reliability. The influence in the straight news was strong in order of reliability, likability and understanding level. The outcome of this study will become empirical data in proceeding with seeking a method available for strengthening the function of offering information in news through increasing delivery and impact in information with producing news chosen by consumers.

• Korean Journal of Cleft Lip And Palate
• /
• v.11 no.2
• /
• pp.49-58
• /
• 2008

The development of fetal surgery has led to promising options for many congenital malformations, such as congenital diaphragmatic hernia (CDH), obstructive uropathy, twin-to-twin transfusion syndrome (TTTS), and sacrococcygeal teratoma. However, preterm labor (PTL) and premature rupture of membranes continue to be uniquitous risks for both mother and fetus. To reduce maternal morbidity and the risk of prematurity, minimal access techniques were developed and are increasingly employed recently. Lift-threatening diseases as well as severely disabling but not life-threatening conditions are potentially amenable to treatment. Recently, improvement of video-endoscopic technology has boosted the development of operative techniques for feto-endoscopic surgery, which has been demonstrated to be less invasive than the open approach. Fetal surgery for repair of cleft lip and palate, a congenital anomaly which is not life threatening, is inappropriate until such time that the benefits are shown to outweigh the risks of both the procedure itself and preterm delivery. Further animal studies will be needed before intrauterine surgery for humans should be considered. For the better understanding of recent techniques and complications associated with fetal intervention of congenital facial defect patients, we reviewed recent related articles about the current knowledge and new perspectives of experimental fetal fetal surgery in the cleft lip and palate defects.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.347-350
• /
• 2010

With the advent of new media era we are living in the world of motion picture image is not an exaggeration. With the development of the mass media with images and moments that passed the day feeling like part of it is communication. In this era a sensual and shapeable image more than the logical and realistic thinking may be passed. In the act of seeing a moving image, prior to linguistic and conceptual meaning, color and screen configuration delivery and formative element in the change they produce is first recognized. Particular kind of video animation having the narrative structure, this territory effect greatly. the film even more significant effect on the area and linking the image of the scene transitions in the scheme also features a simple means of natural communication functions are being expanded. These transitional effects provide visual pleasure from a simple transition traditional methods. And In terms of narrative functions performed to help a narrative flow of availability, visual representation should continue.

• The Journal of the Korea Contents Association
• /
• v.21 no.10
• /
• pp.127-137
• /
• 2021

YouTube beauty content channels that utilize various topics and formats are undergoing quantitative and qualitative expansion. This study selected the top five channels represeting major domestic and foreign beauty brands, fashion magazines and beauty influencers through Statista and conducted a case study focusing on them. It will connect to a strategy for increasing beauty-related content by comparing content characteristics according to content producers. Also, it will help to reveal what types of content will be appealing more attractive to consumer. The result has shown that the growth of YouTube platforms has transformed passive consumers into new communicators by diversifying sources of product information. In addition, as content of different type was consumed by different producers, producer-oriented content was produced rather than objective journalistic gaze. Therefore, it was found that the delivery of 'brand values' that can strengthen the relationship between consumers and brands along with various entertainment elements that are effective for millennial in the future.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.5
• /
• pp.691-700
• /
• 2021

The IP cameras have rapidly replaced the analog CCTVs as the cameras have the advantages of not only being able to remotely monitor, but also supplying power through the UTP cable, In this paper, we introduce the protocol architecture of the ONVIF standard which is widely applied to the IP camera and other Internet protocols to support it, and implement the ONVIF Device on a commercial board. Although these functions can be controlled by the Client (PC), several functions such as privacy masks, temperature display of the thermal camera, and ROI (Region of Interest) are implemented through a web viewer on the device. Through the experiment, the functions of ONVIF Profile S and web viewer are verified through SOAP messages exchanged between Device (IP camera) and Client program and streamed images.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.21 no.3
• /
• pp.183-188
• /
• 2011

According to increased multimedia data(i.e., MPEG video stream) in mobile application, protecting data becomes an important problem in the multimedia data delivery. SECMPEG is a selective encryption approach for protecting multimedia data. However, the computational overhead of SECMPEG's security level 3 is quite large because it encrypts the whole I-frames whose size is relatively larger than P/B-frames. Therefore, we need to analyze the characteristics of MPEG2 standard and derive an effective encryption of the I-frames. In this paper, we propose a slice-level, selective encryption approach by using the error-propagation characteristics of I-frames by a receiver. Our experimental results show that the proposed approach can reduce the execution time of SECMPEG's security level 3 by a factor of 30 without degradation of the security.

• Journal of Distribution Science
• /
• v.14 no.5
• /
• pp.51-57
• /
• 2016

Purpose - In the year of 2015 and 2016, one of the items that got attention in CES was a drone. It has been 100 years since a drone emerged, but most were used for military purposes. As its use became diverse as of 2010, it got attention of the general public. In Korea, it was in 2011 that a drone was known to the public through an aerial video shooting for television program. This study tried to come up with suggestions by comparing domestic with overseas cases, and tried to consider the related technologies and systems with applying the role of drones in logistics service. Research design, data, and methodology - The overseas cases were regarded as drone's logistical purpose. The Prime Air service by US Amazon is still not commercialized and under pre-testing due to Federal Aviation Regulations, although it started in 2013. In Germany, DHL succeeded in delivering service testing which is called Parcelcopter, but it is not commercialized yet. Other than these, there are more attempts to prepare logistics service in China with Taobao, in France with Geopost's test, and in Africa. In Korea, CJ Korea Express tested delivery with a self-developed drone Results - In order to study for utilizing drones for logistics as the prerequisites, some overseas and domestic cases, which are currently considered, were reviewed. Also, the technologies and institutional requirements to commercialize drones for logistical purpose were reviewed. The reasons for using drones in logistics is to ensure the price competitiveness by reducing cost. The empirical test also will be needed because drone pilot areas are designated by ministry of land, infrastructure and transport. Conclusions - In order to utilize drones in logistics and foster the industry, this study would like to suggest the followings. First of all, size of drones for logistics needs to be fixed and their operating system should be standardized. Centralized investment resources are needed through standardization to ensure the market occupancy. Secondly, it is necessary to get the converged businesses that do research, develop and commercialize drones with the investment of private sector. Example can be found in Korea aerospace Industries. We can respond to the rapid growth of the market with intensive investing by integrating the private sector investment. Thirdly, institutional arrangements are needed to be established quickly. In the case of high-technologies like drones, institutional support often does not follow the rapid development of the technology. The problems can be found in securing drones-only airspace, creating drone-specialized pilot's license, matters related to remote controller and complementary regulations for drones in Aviation Act. If these regulations are not prepared or complemented at the right timing, technologies cannot be commercialized even though the development is completed. Fourthly, there is a need to secure the transparency regarding possible privacy and personal information protection problem while operating drones. Finally, in order to foster this new industry, government should focus on supporting R&D more in the long term than short term outcomes.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.248-251
• /
• 2002

The intensity modulated radiation therapy (IMRT) with a multileaf collimator (MLC) requires the conversion of a radiation fluence map into a leaf sequence file that controls the movement of the MLC during radiation treatment of patients. Patient dose verification is clinically one of the most important parts in the treatment delivery of the radiation therapy. The three dimensional (3D) reconstruction of dose distribution delivered to the target helps to verify patient dose and to determine the physical characteristics of beams used in IMRT. A new method is presented for the pretreatment dosimetric verification of two dimensional distributions of photon intensity by means of Beam Intensity Scanner System (BISS) as a radiation detector with a custom-made software for dose calculation of fluorescence signals from scintillator. The scintillator is used to produce fluorescence from the irradiation of 6MV photons on a Varian Clinac 21EX. The BISS reproduces 3D- relative dose distribution from the digitized fluoroscopic signals obtained by digital video camera-based scintillator(DVCS) device in the IMRT. For the intensity modulated beams (IMBs), the calculations of absorbed dose are performed in absolute beam fluence profiles which are used for calculation of the patient dose distribution. The 3D-dose profiles of the IMBs with the BISS were demonstrated by relative measurements of photon beams and shown good agreement with radiographic film. The mechanical and dosimetric properties of the collimating of dynamic and/or step MLC system alter the generated intensity. This is mostly due to leaf transmission, leaf penumbra and geometry of leaves. The variations of output according to the multileaf opening during the irradiation need to be accounted for as well. These phenomena result in a fluence distribution that can be substantially different from the initial and calculative intensity modulation and therefore, should be taken into account by the treatment planning for accurate dose calculations delivered to the target volume in IMRT.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2005.04a
• /
• pp.59-63
• /
• 2005

Respiration motion causes movement of internal structures in the thorax and abdomen, making accurate delivery of radiation therapy to tumors in those areas a challenge. Accounting for such motion during treatment, therefore, has the potential to reduce margins drawn around the clinical target volume (CTV), resulting in a lower dose to normal tissues (e.g., lung and liver) and thus a lower risk of treatment induced complications. Among the techniques that explicitly account for intrafraction motion are breath-hold, respiration gating, and 4D or tumor-tracking techniques. Respiration gating methods periodically turn the beam on when the patient's respiration signal is in a certain part of the respiratory cycle (generally end-inhale or end-exhale). These techniques require acquisition of some form of respiration motion signal (infrared reflective markers, spirometry, strain gauge, thermistor, video tracking of chest outlines and fluoroscopic tracking of implanted markers are some of the techniques employed to date), which is assumed to be correlated with internal anatomy motion. In preliminary study for the respiratory gating radiation therapy, we performed to measurement of this respiration motion signal. In order to measure the respiratory motion signals of patient, respiration measurement system (RMS) was composed with three sensor (spirometer, thermistor, and belt transducer), 4 channel data acquisition system and mobile computer. For two patients, we performed to evaluation of respiratory cycle and shape with RMS. We observed under this system that respiratory cycle is generally periodic but asymmetric, with the majority of time spent. As expected, RMS traced patient's respiration each other well and be easily handled for application.