• Bulletin of the Korean Chemical Society
• /
• v.32 no.8
• /
• pp.2677-2682
• /
• 2011

Direct nitrolysis of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3,3,1]nonane (DPT) is a feasible way to synthesize HMX, and it has multiple practical applications. In this paper, a new nitrolysis process involving the use of an $N_2O_5-HNO_3$ system catalyzed by acidic ionic liquids (AILs) was developed. The results show that [$Et_3NH$]TsO was the best catalyst among the 28 AILs used and that HMX was formed at a higher yield of 61%, compared to 45% without any AIL. Moreover, with the addition of $N_2O_5$, the yield was further increased to a maximum value of 69%. The AILs were also efficiently recovered by simple extractions without any apparent loss of catalytic activity, even after five runs.

• Journal of applied mathematics & informatics
• /
• v.22 no.1_2
• /
• pp.453-460
• /
• 2006

A discrete-time priority queueing system with place reservation discipline is studied, in which two different types of packets arrive according to batch geometric streams. It is assumed that there is a reserved place in the queue. Whenever a high-priority packet enters the queue, it will seize the reserved place and make a new reservation at the end of the queue. Low-priority arrivals take place at the end of the queue in the usual way. Using the probability generating function method, the joint distribution of system state and the delay distribution for each type are obtained.

• Proceedings of the KIEE Conference
• /
• 1998.07c
• /
• pp.1137-1139
• /
• 1998

Effective database is the key to manage automatic distribution system. Currently, automatic distribution system database has been studied with a relational concept. But, it is hard to describe the characteristic of automatic distribution system data which require real time management and composite type. This paper present the way how to design conceptual schema for EMS database using object-oriented concept which is free to decribe composite data type and support inheritance concept.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.671-674
• /
• 2012

Recently, depending on the development of smart devices, a variable services have been offered to meet user's convenience. Due to these advance, the needs of users are extremely being diversified and more specific. In that situation, the needs for the N-Screen system has been varied and gradually evolved. An existing N-Screen system that use the way of video streaming upload its multimedia contents to their own cloud server so that might take a long play-reaction time and the number of user is limited by the server's performance. Because of the web based protocol adopted by existing N-Screen system, there are many different problems like high delay, overhead and something caused by simplex data communications. Therefore, to solve the problems above, this study proposes an application based on HTML5. This application supports Video tag and Progressive download via HTML5 so that improves the play-reaction time for multimedia contents. This system can also get rid of the chronic problems such as an access limitation for lots of users as per video streaming encoding. Also, through web sockets, this study proposes a system that has lower delay than the existing system and communicates in full duplex to be able to link dynamically.

• Journal of Korean Critical Care Nursing
• /
• v.10 no.3
• /
• pp.53-64
• /
• 2017

Purpose : This study investigated the effects of active warming using a Warm Touch warming system or a cotton blanket in postoperative patients after general anesthesia for abdominal surgery. Methods : This quasi-experimental study utilized two experimental groups and one control group: a cotton-blanket group (n = 25) were warmed with a cotton blanket and a sheet; a forced-air warming group (n = 24) were warmed with a Warm Touch warming system, a cotton blanket, and a sheet; and a control group (n = 25) were warmed with a sheet. Measurement variables were postoperative pain, body temperature, and thermal discomfort. Data were analyzed using a one-way ANOVA, ${\chi}^2-tests$, Fisher's exact test, and a repeated measures ANOVA. Results : The effects of active warming using a Warm Touch warming system and a cotton blanket on postoperative patients was significant in reducing pain (F = 13.91, p < .001) and increasing body temperature (F = 12.49, p < .001). Conclusion : Active warming made a significant difference in pain and body temperature changes. Active warming methods may help patients' postoperative recovery and prevent complications. Further research is needed to explore the effects and side effects of active warming on recovering normothermia.

• Korean Journal of Health Education and Promotion
• /
• v.31 no.2
• /
• pp.55-64
• /
• 2014

Objectives: This study is to identify the effects of utilizing a telemedicine service system on patients with hypertension at home in rural areas. Methods: The study was designed to be a retrospective case-control study. The subjects of this study were 152patients with hypertension who were managed by community health practitioner posts; using telemedicine service system group (n=76), usual care group (n=76). The data was collected through EMR (electric medical record) from September to December, 2013, and analyzed by descriptive statistics of $x^2$/t-test and ANCOVA. Results: The analysis showed that telemedicine service system was an effective way to deal with body weight (F=4.723, p=.031) and BMI (F=5.225, p=.024). Conclusions: This study provides evidence for utilizing the telemedicine service system based on information technology as intervention method in the hypertension management.

• Journal of the Korean Magnetic Resonance Society
• /
• v.23 no.4
• /
• pp.104-107
• /
• 2019

Many proteins are expressed as an insoluble form during the production using Escherichia coli (E. coli) system. Although various methods are applied to increase their amounts of soluble expression, refolding is the only feasible way to obtain a target protein in some cases. Moreover, protein NMR experiments require ¹³C/¹⁵N-labeled proteins that can only be obtained from E. coli systems in terms of cost and technical difficulty. The finding of appropriate refolding conditions for a target protein is a time-consuming process. In particular, it is very difficult to determine whether the refolded protein has a native structure, when a target protein has no enzymatic activity and its refolding yield is very low. Here, we showed that 1-dimensional ¹H-¹⁵N heteronuclear single quantum correlation (1D ¹H-¹⁵N HSQC) experiment can be efficiently used to screen an optimal condition for the refolding of a target protein by monitoring both the structure and concentration of the refolded protein.

• Korean Management Science Review
• /
• v.9 no.1
• /
• pp.3-15
• /
• 1992

In this paper, we study a manufacturing system of serial stages with general service times, in which the production of each stage and the coordination of stages are controlled by Kanban discipline. This Kanban discipline is modeled as a Discrete Event Dynamic System and a system of recursive equations is applied to study the dynamics of the system. The recursive relationship enables us to compare this Kanban discipline with the other blocking disciplines such as transfer blocking, service blocking, block-and-hold b, and block-and-hold K, and the Kanban is shown to be superior to the other disciplines in terms of makespan and throughput. As a special case, two stages Kanban system is modeled as $C_2/C_2/1/N$ queueing system, and a recursive algorithm is developed to calculate the system performance. In optimizing the system performance, the stochastic optimization approach of Robbins-Monro is employed via perturbation analysis, the way to estimate the stochastic partial derivative based on only one sample trajectory of the system, and the required commuting condition is verified. Then the stochastic convexity result is established to provide second-order optimality condition for this parametric optimization problem.

• Journal of Environmental Impact Assessment
• /
• v.26 no.6
• /
• pp.508-523
• /
• 2017

This study monitored the changes before and after restoration of ecological stream focusing on the places which are applied Sustainable Structured wetland Biotop (SSB) system and ecological Fish-way for restoration of Maeno stream. A total of 11 species and 191 individuals of fishes were founded out which were not verified inhabitation before restoration at SSB wetlands. Especially, it was could identified that micro habitat and healthy Fish-way was created because the restored target species, Microphysogobio yaluensis and Iksookimia koreensis were identified that habitation was monitored in SSB wetland. Amphibian have been restored to a number of Rana nigromaculata found in and around wetlands at the time of the third survey, which is highly active after restoration. Specified endangered species class 1 and natural monuments designated by the Ministry of Environment, Lutra lutra lutra, as a Mammalian, uses the wetlands and ecological Fish-way as habitat areas, and the his habitat is restored. In the case of Flora, vascular plants emerging in the survey area were increased to 7 and 13 species before restoration and 15 and 19 species directly after restoration, and 22 species and 33 species after restoration. Vegetation after restoration was found to be a basic producer of various ecosystems and a plant community that contributes to the purification of water quality such as Phragmites japonica communities. As the result of water quality monitoring, the average of treatment efficiencies were BOD 64.3%, T-N 47.2%, T-P 80.7%. Successful treatment of the nonpoint pullution source, which is a limiting factor to disturb the ecosystem, creatively restored the target species in the water quality class I, II.

• Journal of Surface Science and Engineering
• /
• v.36 no.3
• /
• pp.284-289
• /
• 2003

In this study, the prediction on the quality of tools after coating process has been investigated. Under different coating conditions, cutting resistances have been obtained and analyzed with a tool dynamometer to provide optimized coating conditions. The optimized coating conditions Lhave been computed with the most effective factors found by S/N ratio of Taguchi method. To evaluate the influence of the factors on cutting efficiency through the minimum of number of experiment times, the way of neural network design using Taguchi method has been employed.