• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.5A
• /
• pp.464-472
• /
• 2011

As wireless sensor networks are applied to various applications such as environment monitoring and disaster sensing system, there are increased needs for wireless communication in underground environment. Since the previous wireless communication technology using electromagnetic wave is not appropriate for the underground environment, a new alternative is required. Recently a magnetic field communication technology has been proposed and standardized as a domestic KS standard. In this paper, we analyze the media access control protocol of the KS standard by an analysis and a simulation study.

• International journal of advanced smart convergence
• /
• v.5 no.3
• /
• pp.61-65
• /
• 2016

In the TV broadcasting, movie production and business the transportation of video between creators (programmers, studios) and distributors (broadcast and cable networks, cable and satellites companies) is still a mix of File Transfer Protocol (FTP), physical delivery, and expensive multicast satellite. Cloud-based file sync-and-share providers like Dropbox and box are playing an increasing role, but the industry's unique demands for speed and multicasting have fueled the growth of IP Video transport. This paper gives a solid grasp of the major elements of IP video technology, including content preparation, system architecture alternatives and network performance management.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.8
• /
• pp.45-53
• /
• 2004

This paper proposes and analyzes a new media access control (MAC) scheduling algorithm, “Interleaved Polling with Deficit Round Robin (IPDRR)” that supports weighted fairness among ONUs in Ethernet Passive Optical Network (PON). The purpose of the proposed IPDRR algerian is not only to eliminate the unused bandwidth of upstream ONU traffic, but also to provide weighted fair sharing of upstream bandwidth among ONUs in Ethernet PON systems. Simulation results show that the IPDRR improves the utilization of upstream channel by removing the unused bandwidth and provides weighted fairness among ONUs, although the IPACT scheduling is unfair according to traffic characteristics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2002.11a
• /
• pp.844-848
• /
• 2002

In this paper, we present a VoIP service provisioning architecture based on MEGACO/H.248 which is one of the key protocols for VoIP services. MEGACO/H.248 is a media gateway control protocol standardized by both ITU-T and IETF, and many ITSPs, carriers, and vendors currently have a lot of interest in the protocol. MEGACO/H.248 is used by a softswitch a key component of the next generation VoIP network, in order to control various media gateways and provide seamless interworking between PSTN and Yon networks.

• Educational Technology International
• /
• v.23 no.2
• /
• pp.183-205
• /
• 2022

Mental status examination is an important stage in the assessment process because it serves as the foundation for establishing nursing diagnosis and intervention. Until now many students still feel difficult to understand the terms in the assessment of mental status. Interactive Mobile Learning in one of the media that is currently being developed. The use of this media will provide more in-depth learning opportunities, and students can practice their skills in carrying out practicals because of the mobility principle possessed by smartphones. The purpose of this study was to develop a smartphone-based app and evaluate the app's effectiveness by measuring nursing students' knowledge of mental status examination. Design: A randomized trial with a pre-and post-test design was conducted at a university in Indonesia. A total of seventy junior nursing students participated in this study. The intervention group received a smartphone-based app, and the control group received one-time lecture-based learning. We offered the experimental group the app and information about how to use it, and we encouraged them to use it. The control group received classroom instruction. Results: The intervention group scored significantly higher than the control group on knowledge score (t = 19.40, p = 0.000) and satisfaction with the learning method (t = 0.640, p = 0.021) Conclusion: These findings suggest that smartphonebased education could be an effective method in nursing education for teaching mental status examinations.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.6
• /
• pp.607-613
• /
• 2009

In this paper, we made a simple paper feeding system which is one of MTS (media transport system) and controllers. The plant has a flexible paper and two driving rollers and two driven rollers. The control system has two conventional PID controllers. Skew angle and feeding speed of MTS deteriorate the quality of feeding system. In order to control a feeding speed and skew of feeding paper, we control rotational velocity of two driving rollers. Therefore, this controller has two inputs and two outputs as MIMO (multi-input and multi-output) system. The control inputs were the feeding speed and the skew displacement of the paper. The control outputs were the rotational velocity to each driving roller. To find appropriate PID gains of two controllers, we proposed an optimization technique. We assume the system variables and performance of a whole system as follows. PID gains of two controllers for skew and feeding speed are system variables. System performance is both skew and feeding speed. We simulates to making mathematical correlation using global Kriging interpolation. To find appropriate value of system variables, optimization method is simulation in sequence as following method. First, the optimization solver simulates with DOE (design of experiment) tables to find correlation equation of both system variable and performances. Then, the solver guesses the appropriate values and simulates if the system variables are appropriate or not. If the result of validation doesn't satisfy the convergence and iteration tolerance, the solver makes a new Kriging models and iterates this sequence until satisfy the tolerances.

• Korean Journal of Environmental Agriculture
• /
• v.19 no.3
• /
• pp.234-241
• /
• 2000

For the recycling of sludge as soil conditioner, the firing technology in pottery industry was applied to the sludge treatment, and produced artificial media with many voids. To produce artificial media using sludge, chabazite and lime were used as additives, and the mixture of sludge and additives was thermally treated in the firing kiln at about $800{\sim}1,100^{\circ}C$ for about ten minutes. The effect of mixed artificial media into upland soil was investigated through the crop growth experiment and the physical & chemical characteristics of the mixed soils were analysed. The pH of artificial media was higher than that of the control soils. After the plant growth experiment, artificial media plots almost contained more CEC, OM, TN, TP and $AV.P_2O_5$ than upland soil plots. From the growth analysis, growth of soybean and corn in the artificial media plots was better than that in the original upland soil plots. The yield of soybean and corn in the artificial media plots were about 46kg/10a, 194kg/10a, respectively, which is higher than that in the control. Heavy metals in the artificial media plots were lower than the standard regulation. Therefore, the artificial media produced from sludge can be mixed into farmland, and crop production can be increased additionally.

• Journal of Bio-Environment Control
• /
• v.15 no.4
• /
• pp.317-321
• /
• 2006

The experiment has investigated the effects of growth, yield, and fruit quality of strawberries by three different kinds of substrates. Commonly used media cocopeat, cocopeat mixed with rice hulls and compound nursery media were used to select a proper medium by comparing growth status, yield and fruit quality. Number of leaves was most in cocopeat substrate, and leaf length and leaf width were highest in compound nursery media. Fruit weight was heaviest in compound nursery media, but there were no significant statistical differences in fruit length, fruit width and soluble solids of fruit. Number of fruits per plant was much in compound nursery media and cocopeat than cocopeat mixed with rice hulls. The most yield per plant was in compound nursery media and the least it was in cocopeat mixed with rice hulls. The results of this experiment will be utilized in the new substrate application for strawberry hydroponics.

• Journal of Bio-Environment Control
• /
• v.15 no.1
• /
• pp.8-20
• /
• 2006

This research was conducted to determine the plant growth and nutrient contents of potted chrysanthemum 'Lima Honey' as influenced by application rate of dolomite in three root media, peatmoss+vermiculite (1:1, v/v), peatmoss+composted rice hall (1:1, v/v), and peatmoss+composted pine bark (1:1, v/v). All root media contained polyacrylic acid sodium salt (PASS) at a rate of $4.5g L^{-1}$. In crop growth at 40 and 80 days after transplanting, elevated application rates of dolomite up to $6.0g L^{-1}$ in three root media increased fresh and dry weights per plant. But the treatment of $9.0g L^{-1}$ had less fresh and dry weights than those of $6.0g L^{-1}$. Tissue phosphorus content decreased and those of Ca and Mg increased by the elevated application rates of dolomite. Elevated application rates of dolomite in three root media resulted in the increase of pH, EC, and the concentrations of K, Ca, and Mg at 43 days after transplanting. Those at 80 days after transplanting were also increased, but the differences among treatments were less significant as compared to those at 43 days after transplanting. From the results of dry weight in potted chrysanthemum 'Lima Honey', the proper application rate of dolomite to three root media containing PASS at a rate of $4.5g L^{-1}$ were $6.0g L^{-1}$.

• Clinical and Experimental Reproductive Medicine
• /
• v.20 no.1
• /
• pp.9-17
• /
• 1993

This study was carried out investigate the effect of water quality and the kind of media on the in vitro development of 1-cell and stage mouse embryos. $F_1$ hybrid mice were superovulated and timely mated. 1-cell stage and 2-cell stage mouse embryos were recruited and taken into Ham's F-10 or m-KRB media which was made of two of two kinds of water having different quality, highly purified water and tap water. 2-cell stage embryos grew up well in vitro to blastocyst or hatching blastocyst regardless of the composition of culture media, but 1-cell stage mouse embryo didn't develop well to blastocyst or hatching blastocyst in simple media like m-KRB. These results meant in vitro devleopment of 1-cell stage mouse embryo neded complex media like Ham's F-10 which contained abundant protein components. In case of quality control for water, in vitro fertilization program. observation of in vitro development of 2-cell mouse embryos up to blastocyst or hatching blastocyst media such as m-KRB would be efficatious in detecting the difference of water quality.