• Journal of Digital Convergence
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• v.11 no.7
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• pp.255-260
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• 2013

This study was attempted to identify the differences of mental health and media use according to the addiction of communication media. Data collection was surveyed using interview and questionnaires by 250 subjects from March 12 to May 13, 2012. The results were as follows : First, with regard to mobile phone use time for communication in the use of over 2 hrs, subjects replied that addictive group was significantly higher than non-addictive group($X^2$=8.51, p=.00). Secondly, in case often depression, the risk ratio of addictive group was significantly higher 4.0 times than non-addictive group(OR=4.0, 95%, Cl=2.4-36.9). In conclusion, in order to prevent the addictive use of communication media, it is needed to make various environment such as sound life rhythm maintenance, systemic and periodic education.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1214-1221
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• 2006

Header compression scheme is suggested as a solution to reduce the inefficient overhead of general packet stream data. Especially, it is shown that there are more overhead rate for real-time media stream links such as voice because of its short payload size, and it is possible to get higher bandwidth efficiency using the header compression scheme. There are two kinds of error recovery in header compression such as Periodic Header Refresh(PHR) and Header Request(HR) schemes. In this paper, we analyze the performance of these two compression recovery schemes, and some results such as the overhead rate, bandwidth gain and bandwidth efficiency(BE) are presented.

• Journal of Digital Convergence
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• v.11 no.8
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• pp.183-190
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• 2013

The Photoplethysmogram is a similar periodic signal that synchrinized to a heartbeat. In this paper, we propose a exponential weight moving average filter that use similarity of Photoplethysmogram. This filtering method has the average value of each samples through separating the cycle of PPG signal. If there are some motion artifacts in continuous PPG signal, disjoin the signal based on cycle. And then, we made these signals to have same cycle by coordinating the number of sample. After arrange these cycles in 2 dimension, we put the average value of each samples from starting till now. So, we can eliminate the motion artifacts without damaged PPG signal.

• Advances in aircraft and spacecraft science
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• v.6 no.6
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• pp.479-495
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• 2019

Periodic cellular core structures included in sandwich panels possess good stiffness while saving weight and only lately their potential to act as passive vibration filters is increasingly being studied. Classical homogeneous honeycombs show poor vibracoustic performance and only by varying certain geometrical features, a shift and/or variation in bandgap frequency range occurs. This work aims to investigate the vibration filtering properties of the AUXHEX "hybrid" core, which is a cellular structure containing cells of different shapes. Numerical simulations are carried out using two different approaches. The first technique used is the harmonic analysis with commercially available software, and the second one, which has been proved to be computationally more efficient, consists in the Wave Finite Element Method (WFEM), which still makes use of finite elements (FEM) packages, but instead of working with large models, it exploits the periodicity of the structure by analysing only the unit cell, thanks to the Floquet-Bloch theorem. Both techniques allow to produce graphs such as frequency response plots (FRF's) and dispersion curves, which are powerful tools used to identify the spectral bandgap signature of the considered structure. The hybrid cellular core pattern AUXHEX is analysed and results are discussed, focusing the investigation on the possible spectral bandgap signature heritage that a hybrid core experiences from their "parents" homogeneous cell cores.

• Journal of Broadcast Engineering
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• v.14 no.2
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• pp.189-196
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• 2009

We propose a hybrid broadcast scheduling based on a combination of periodic and on-demand data scheduling methods for mobile data broadcasting in convergence networks from communication and broadcasting. We consider an environment in which the forward channel is for data broadcasting and the reverse channel is for sending data requests via cellular phones, WLAN, WiBro, etc. Collecting statistics of requests from clients, the server partitions the data items into hot-item and cold-item sets. Hot items are sent based on a push-based scheduling. An on-demand scheduling method is applied to cold items. Performance evaluation from simulations shows that our proposed scheduling algorithm yields small response time with high successful response ratio.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.4
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• pp.403-410
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• 2010

The switched Ethernet has many features for real-time communications such as providing traffic isolation, large bandwidth, and full-duplex links, and so on. The switched Ethernet, however, cannot guarantee the timely delivery of a real-time message because message delay increases when collisions occurs at the output ports and message loss can even occur due to the overflow at the output buffer. Recently, many research efforts have been done to use the switched Ethernet as an industrial control network. In the industrial control network, sensors periodically sense the physical environment and transmit the sensed data to an actuator, and the periodic messages from sensors to actuators have typically real-time requirements such that those messages must be transmitted within their deadlines. This paper first suggests a feasible condition for EDF (Earliest Deadline First)-based scheduling of periodic messages on a synchronized switched Ethernet and a message scheduling algorithm which satisfies the proposed feasible condition. Pedreiras, et al. [10] suggested a feasible condition for message scheduling on the Ethernet (shared media Ethernet), but there has been no research result on the scheduling condition on the switched Ethernet until now. We compared the real-time message scheduling capacity between the Ethernet and the switched Ethernet by simulation. The simulation result shows that the message scheduling capacity of the Ethernet has almost remained constant as the number of nodes on the network increases, but, in the case of the switched Ethernet, the message scheduling capacity has increased linearly according to the number of nodes on the network.

• Korean Journal of Community Nutrition
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• v.7 no.2
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• pp.266-276
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• 2002

In this study, a computerized nutritional and health guide program for workers was developed. The dietitian at the work site could utilize periodically conducted medical examination data to develop an effective health care counseling model based on the developed Nutritional and Health Guide Program. A personal computer (Pentium II PC MMX-150, 32MB RAM, 2.95 GB HDD) with Microsoft Visual Basic 6.0 Enterprise Edition and Microsoft Access 97 installed, was used. The Nutritional and Health Guide Program consisted of seven main menus and 43 sub-menus. Included in the main menu were Basic Information, Periodic Health Check-ups, Visitors' Consultations, Nutritional/Health Tips, Nutritional Education according to Diseases, Help and Exit. In the Periodic Health Check-up menu, dieticians could input the health examination data of employees and touch for the recommended treatments for diseases such as obesity, diabetes, high cholesterol, hypertension and hepatitis. The Visitors'Consultation menu has been designed to compile health information about the employees who sought consultations. The Nutritional/Health Tips menu was designed to provide 14 kinds of programmed nutritional educational media and information. In the Nutritional Education According to Diseases menu, the dietitian could judge the subject's willingness to obtain treatment based on the Stage of Change Model. According, the content of the administered respective nutritional education was classified by stages. The Help menu, provide a chart of the method and procedure used as nutritional guidelines, by which the results of the health examination were classified as people in good health and those requiring special medical attention. The results of the evaluation of this program showed highly positive rates for usefulness (4.09), convenience (4.04), lettering size (4.02), interest (3.93), design (3.49). It also showed that 97.5% of the subjects thought that this program would be helpful for implementation of their company's nutritional educational program. Therefore, this menu could help dietitians plan, conduct, and evaluate their nutritional guidelines for employees. It is expected that The Nutritional and Health Guide Program developed in this study will play a role as a scientific and effective guide in conjunction with health examination results.

• Korean Journal of Cleft Lip And Palate
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• v.10 no.2
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• pp.89-96
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• 2007

Otitis media with effusion is known to be very common among children with cleft palate and is the common cause of acquired hearing loss in childhood. The purpose of the present study was to examine the anatomic variances, incidence and treatment of middle ear disease in children with cleft palate. In Korea, before 4-year-old age, the prevalence of otitis media was as high as 91.7%. Common treatments for otitis media were conservative or surgical treatment. The medical treatment options include the use of decongestants, antihistamines, antibiotics and mucolytics. Surgical treatment options include grommet insertion, myringotomy. Unlike the case for children without clefts, cleft patient has a higher incidence of recurrence, so surgical treatment between the age of 3 month and 6 month was recommended. The effect of palatoplasty on middle ear disease has remained controversial. Early and periodic evaluation on the symptomatic infection or significant of hearing loss was recommended.

• Tunnel and Underground Space
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• v.22 no.4
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• pp.243-256
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• 2012

Developing efficient and reliable energy storage system is as important as exploring new energy resources. Energy storage system can balance the periodic and quantitative mismatch between energy supply and energy demand and increase the energy efficiency. Industrial waster heat and renewable energy such as solar energy can be stored by the thermal energy storage (TES) system at high and low temperatures. TES system using underground rock carven is considered as an attractive alternative for large-scale storage, because of low thermal conductivity and chemical safety of surrounding rock mass. In this report, the development of available thermal energy storage methods and the characteristics of storage media were introduced. Based on some successful applications of cavern storage and high-temperature storage reported in the literature, the applicabilities and practicabilities of storage media and technologies for large-scale cavern thermal energy storage (CTES) were reviewed.

• Korean journal of applied entomology
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• v.4
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• pp.19-24
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• 1965

In an attempt to find a satisfactory environmental factors which facilitate abundant conidial production of Piriculariaoryzae Cav. on tomato juice media, various environmental factors were studied for their effect on sporulation and mycelial growth of the fungus. Those factors were conditions of irradiation, color of light, age of culture and pH of the media. l) Continuous exposure to fluorescent light (Mitsubish FL-20-35 W) produced more conidia and much mycelial growth than did intermittent photoperiods and darkness. 2) Of 3 cellophane filters and direct exposure to fluorescent light used, conidia were produced best under the direct exposure to the light. Conidial production in color filter conditions sequently decreased with red, yellow and blue. Growth of mycelium was not significantly different within colors. 3) Periodic irradiation of 12-hour unit brought about zones on mycelial growth no matter what the color filter was used. 4) Older cultures responding to the light were more stimulated by light than were the younger one in the conidia production, but maximum production of conidia was 48 hours of age in this case. 5) Color of the mycelial mat and the aerial mycelium seemed to have a close relation to the production of conidia. The more darkness of the mycelial mat was produced the more conidia and the much aerial mycelium was produced the least conidia. The color of mycelium was more dark under the continuous irradiation than continuous darkness, while the periodic irradiation showed intermediate effect. 6) The concentration of hydrogen ion for growth and sporulation of the fungus was investigated the ranges between 5 and 9. The best pH for the fungus was also noted at 7. whereas the below of pH 4 was not occurred any mycelial growth and sporulation.