• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.3
• /
• pp.343-354
• /
• 2012

In this paper, various spiral zeroth-order resonators are proposed for wireless power transmission. Since a zerothorder resonance(ZOR) mode of meta-material transmission lines has the characteristic of an infinite wavelength, its frequency is independent of physical length. Also, to obtain high transmission efficiencies high-Q resonators and strong coupling coefficient between coupled resonators are required. Therefore, the resonators consist of spiral inductor and lumped capacitor to use the ZOR mode and they are optimized via parametric study and circuit analysis for a high-Q resonator design. The optimized resonators are simulated and compared with a conventional spiral resonator and one of them was fabricated and measured. The fabricated one has a dimension of $20cm{\times}20cm{\times}8cm$($0.009{\lambda}_0{\times}0.009_{\lambda}_0{\times}0.004{\lambda}_0$) and the transmission efficiency of 80 % is measured at 13.56 MHz at transmitted distance of 40 cm.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.6
• /
• pp.33-39
• /
• 2023

Recently, reinforcement learning has been used to improve the communication performance of flying ad-hoc networks (FANETs) and to design mobility models. Mobility model is a key factor for predicting and controlling the movement of unmmaned aerial vehicle (UAVs). In this paper, we designed and analyzed the performance of Q-learning with fourier basis function approximation and Deep-Q Network (DQN) models for optimal path finding in a three-dimensional virtual environment where UAVs operate. The experimental results show that the DQN model is more suitable for optimal path finding than the Q-learning model in a three-dimensional virtual environment.

• Ocean and Polar Research
• /
• v.36 no.1
• /
• pp.39-47
• /
• 2014

The black scraper Thamnaconus modestus was a commercially important fish species in the 1980s, but suddenly its commercial significance decreased in the 1990s mainly due to continuous overfishing. Recently, in order to reverse the depleted stocks of the black scraper and help the species recover, seed production technology has emerged. This has led to the farming of the black scraper in several parts of the southern coast of Korea. Since detailed research on its metabolism in relation to water temperature has been scanty, this was the investigative focus of the present study. The standard metabolism rates of the black scraper (9-10 months old, total length=$22.6{\pm}0.8cm$, wet weight=$140.3{\pm}13.9g$) were measured at seven different water temperature settings (12, 15, 17, 20, 23, 26, $28^{\circ}C$) to understand the relationship between metabolism and water temperature. Relationships between water temperature (WT) and oxygen consumption rate (OCR) were obtained as SOCR (weight-specific oxygen consumption rate) = 0.0117WT - 0.0135 ($r^2=0.9351$) and IOCR (oxygen consumption rate per individual) = 1.8160WT - 5.4007 ($r^2$ = 9428). The $Q_{10}$ (temperature sensitivity), an indicator of the sensitivity of biological function to temperature, was analyzed. In our experiment, when the water temperature increased, the $Q_{10}$ value decreased. The $Q_{10}$ value was 6.27 in waters where the temperature ranged from $12-15^{\circ}C$ and this was much higher than the values obtained in waters where temperatures ranged between (1) $15-23^{\circ}C$ and (2) $23-28^{\circ}C$. Consequently, it was shown that the black scraper is a warm water species and inhabiting waters in the temperature range from $15-28^{\circ}C$ is deemed appropriate.

• Journal of Energy Engineering
• /
• v.10 no.4
• /
• pp.379-386
• /
• 2001

This experimental study deals with on Nitric Oxide Formation & Reduction in Industrial Bunner. In this study, Laser-induced fluorescence (LIF) techniques have been used for quantitative measurements of Nitric Oxide. The NO A-X (0, 0) Vibrational band around 226 nm was excited using a XeCl excimer-pumped dye laser. And on-line excitation used $P_{21}+Q_1(14.5)/R_{12}+Q_2(20.5)/P_1(23.5)$ transition, for minimizing the other interferential effect. The measurements were taken NO concentration distribution in double swirling diffusion flame. In this swirl burner, NO concentration in downstream fo the flame decrease as primary/secondary air ratio increases.

• Korean Journal of Human Ecology
• /
• v.23 no.2
• /
• pp.205-217
• /
• 2014

This study examined attitudes of grandmothers who had experience in grandchild care in order to explore their subjectivity. Research questions were 1) to categorize the attitudes toward grandchild care, and 2) to analyze each type's characteristics and elucidate the analyses. The results are as follows. Grandmothers' attitudes toward grandchild care were categorized into three types: (1) adjusting-to-role-change type, (2) recognizing-the-role-burdens type, (3) enjoying-the-traditional-role type. Type 1, the adjusting-to-role-change type was aware of positive facets of grandchild care, and actively accepted the caring responsibility, but did not think it was a grandmother's duty to care for the grandchildren or that it was the sole pleasure in a grandmother's life. Type 2, the recognizing-the-role-burdens type, had a negative view regarding grandchild care, perceiving the cost too high relative to the reward. On the other hand, Type 3, the enjoying-the-traditional-role type considered grandchild care as a pleasure and a duty, and downplayed negative aspects such as having no time to herself, assuming the traditional grandmother role and enjoying it. These results imply that the attitudes of grandmothers nowadays are undergoing a change from the traditional grandmother role attitude.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.23 no.3
• /
• pp.268-278
• /
• 2017

Purpose: The purpose of this study was to investigate the subjectivity of undergraduate students about happiness. Methods: Q methodology, which scientifically measures individual subjectivity, was used. Thirty-four Q-statements selected from 40 participants were classified into a shape of normal distribution using a nine-point scale. The collected data were analyzed using a PQMethod PC program. Results: Type I: Self-directed, growth-seeking type. This group of people searches for their objectives and direction in life while consistently making efforts to realize their goals. Type II: Oriental and wealth-seeking type. This group of people sympathizes with the oriental worldview and believes in having luck such as wealth or health. Type III: Realistic and pleasure-seeking type. This group of people tries to think positively but while rooted in reality, searches for pleasure and satisfaction in their surroundings. Type IV: Altruistic and relationship-seeking type. This group of people stresses the importance of religious life, small happiness in life, and relationship with friends or neighbors. Conclusion: The results of this study provide the foundation for understanding college students' perception about their happiness. Furthermore, these results suggest the necessity of specific and integrated education to improve happiness.

• Culinary science and hospitality research
• /
• v.23 no.7
• /
• pp.71-79
• /
• 2017

This paper presented analysis on the perception by Korean restaurant employees of Korean royal cuisine. Classification using a subjective research method called Q methodology was performed on perceptions of Korean restaurant employees about Korean royal cuisine. This paper derived four types of perceptions. First type (pursuit of tradition) emphasized traditions of royal cuisine, i.e. cooking method and spacious menu-setting on the table. The second type (pursuit of refinement) stressed the importance of "atmosphere and luxuriousness of Korean restaurants and sophistication of royal cuisine, as well as the improvement of interior and exterior environments of Korean restaurants serving royal cuisine. The third type (pursuit of fundamentals) focused on fundamentals of royal cuisine itself such as raw materials, sincere effort, historical meaning, appropriate prices, etc. The last type (pursuit of health) valued a nutritionally balanced diet rather than taste itself. This study provides more specific positioning strategy based on the characteristics of each of the four classifications for the status of Korean restaurants.

• Clean Technology
• /
• v.23 no.2
• /
• pp.205-212
• /
• 2017

We investigated the performance of a jet loop reactor (JLR) with the two-fluid venturi-type swirl nozzle (TVSN) during experiment for ammonia removal by air stripping from a synthetic wastewater, and compared it with that of a JLR with the two-fluid venturi-type conventional nozzle (TVCN), with the variation of pH, liquid circulation rate ($Q_L$), and air flow rate ($Q_G$). Their performance levels were compared based on the ammonia removal efficiency and overall mass transfer coefficient ($K_La$). Investigated parameters in a JLR were pH (10-12), air flow rate ($Q_G=5-20L\;min^{-1}$), and liquid circulation rate ($Q_L=25-35L\;min^{-1}$). Throughout the experiment, the ammonia removal efficiency and $K_La$ in a JLR with TVSN was higher than in a JLR with TVCN. This may be due to the enhanced turbulent intensity by swirling flow formed in the JLR with TVSN compared to that with TVCN. Further, we obtained higher $K_La$ when pH, $Q_L$ and $Q_G$ were increased. In particular, $K_La$ was increased more efficiently by increasing $Q_G$ than by increasing pH and $Q_L$.

• Bulletin of the Korean Chemical Society
• /
• v.3 no.1
• /
• pp.23-30
• /
• 1982

For the study of transport phenomena of an aqueous NaCl solution through a cuprophane membrane, a new apparatus was constructed. The volumc flow rate Q, the permeability coefficient U, and the permeability constant K were measured or determined by using this apparatus. The experimental temperature range was 5 to $35^{\circ}C$, and the applied pressure increments were 10 to 40 psi. By assuming that the cuprophane membrane is composed of n parallel cylindrical capillaries of circular cross-section and that the flow of the solution through the capillaries follows the Poiseulle law, the mean radius r of the capillaries and the number n of the latter in the membrane were evaluated. By using a reasonable assumption concerning the radius ${\eta}'$ of the species diffusing through the membrane, it was concluded that the contribution of the diffusive flow to the total flow rate Q is less than 10%. Thus, the Q was treated as the rate due to the viscous flow, and the viscosity ${\eta}_m$ of the solution in the membrane phase was evaluted, and it was found that ηm is nearly equal to ${\eta}_b$, the bulk viscosity of the solution. From this fact, it was concluded that in the capillaries, no change occurs in the physical state of the NaCl solution. The value of ( = 4.27 kcal/mole) and ${\Delta}Sm^{\neq}$(4.28 eu) were obtained for the viscous flow. A possible explanation was given.

• KNOM Review
• /
• v.23 no.2
• /
• pp.1-10
• /
• 2020

Network Function Virtualization (NFV) is a key technology of 5G networks that has the advantage of enabling building and operating networks flexibly. However, NFV can complicate network management because it creates numerous virtual resources that should be managed. In NFV environments, service function chaining (SFC) composed of virtual network functions (VNFs) is widely used to apply a series of network functions to traffic. Therefore, it is required to dynamically allocate the right amount of computing resources or instances to SFC for meeting service requirements. In this paper, we propose Deep Q-Networks (DQN)-based auto-scaling to operate the appropriate number of VNF instances in SFC. The proposed approach not only resizes the number of VNF instances in SFC composed of multi-tier architecture but also selects a tier to be scaled in response to dynamic traffic forwarding through SFC.