• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11b
• /
• pp.1099-1103
• /
• 2001

In room acoustics, reverberation time (RT) is the most important and general factor that represents character of room or inner space. However, RT, especially in low frequency range, can have the different value according to the measuring points and methods. This study comprehends the cause of error occurring dominantly in low frequency range when RT is measured and examines that the each error of RT measured in the cabin and reverberation chamber having different properties, influences what extent on sound transmission loss (STL)

• Journal of Korean Medicine for Obesity Research
• /
• v.3 no.1
• /
• pp.61-67
• /
• 2003

Objectives : To compare the reduction of thigh circumference between electro acupuncture treatment group and no treatment controlled group. Method : Trial was carried out 24 volunteers for 2 weeks. Volunteers were divided into 2 groups ; electro acupuncture and very low calorie diet group(n=8) or only very low calorie diet group(n=9). The main outcome of measure was the reduction of thigh circumference(cm) per weight loss(kg). Result: The main outcome measure showed no significant difference(p=0.14). There was no significant difference in weight loss(p=0.67) either.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.25 no.6
• /
• pp.490-495
• /
• 2020

The power loss of large-capacity systems using single-phase inverters has attracted considerable attention. In this study, optimal switching sequence model prediction control at a low switching frequency is proposed to reduce the power loss in a high-power inverter system, and a compensation method that can be utilized for model prediction control is developed to reduce errors in accordance with sampling values. When a three-level, single-phase inverter using a switching frequency of 600 Hz and a sampling frequency of 12 kHz is adopted, the power factor is improved from 0.95 to 0.99 through 3 kW active power control. The performance of the controller is also verified.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.391-394
• /
• 1998

Telecommunication system demands for increased bandwidths and operating frequencies for analog signal processing could be satisfied in the near future by the emergence of a novel technology based on magnetostatic waves propagating in low loss ferrimagnetic films. The magnetostatic wave n the only available technology for analog signal processing directly at microwave frequencies.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2000.11a
• /
• pp.225-228
• /
• 2000

In this paper, the design for a low noise amplifier with the EM simulation is presented. The ATF36077 pHEMT device is applied to design LNA for U-NII frequency band (5 GHz ～ 6 GHz). The matching networks have been designed by the only open ended stub in order to reduce parasitic effects generated from a via structure. Through EM simulator, the simulation result shows that the linear gain (@5.5 GHz) is over 10 dB, input return loss and output return loss (@ 5.5 GHz) are a below 10 dB respectively, and the 3rd order intercept point is about 17 dBm.

• ETRI Journal
• /
• v.45 no.3
• /
• pp.433-447
• /
• 2023

Critical issues such as connection congestion, long transmission delay, and packet loss become even worse during epidemic, disaster, and so on. In this study, a link load balancing method is proposed to address these issues on the data plane, a plane of the software-defined network (SDN) architecture. These problems are NP-complete, so a meta-heuristic approach, discrete particle swarm optimization, is used with a novel hybrid cost function. The superiority of the proposed method over existing methods in the literature is that it provides link and switch load balancing simultaneously. The goal is to choose a path that minimizes the connection load between the source and destination in multipath SDNs. Furthermore, the proposed work is dynamic, so selected paths are regularly updated. Simulation results prove that with the proposed method, streams reach the target with minimum time, no loss, low power consumption, and low memory usage.

• Archives of Obesity and Metabolism
• /
• v.3 no.1
• /
• pp.9-13
• /
• 2024

The prevalence of obesity has been increasing worldwide. Several dietary treatments have been suggested to control weight, and recent guidelines recommend individualizing the composition of macronutrients. Carbohydrates are the most important nutrients in meals, and carbohydrate restriction is a dietary strategy that promotes weight loss. A low-carbohydrate diet is effective for short-term weight loss and can help improve glycated hemoglobin, systolic blood pressure, diastolic blood pressure, and triglyceride levels; however, the long-term effects and safety of this diet remains doubtful. In the short term, there is a risk of gastrointestinal symptoms such as vomiting, diarrhea, constipation, and gastroesophageal reflux, and type 1 diabetes patients are at risk of severe hypoglycemia, while in the long term, it can lead to malnutrition and decreased exercise capacity. Thus, rather than limiting the intake of carbohydrates, it is important to limit the intake of refined grains, sugar, honey, syrup, and sweetened beverages while maintaining the planned carbohydrate intake rate and improving meal quality.

• Current Photovoltaic Research
• /
• v.7 no.4
• /
• pp.111-120
• /
• 2019

The output power of a crystalline silicon (c-Si) photovoltaic (PV) module is not directly the sum of the powers of its unit cells. There are several losses and gain mechanisms that reduce the total output power when solar cells are encapsulated into solar modules. Theses factors are getting high attention as the high cell efficiency achievement become more complex and expensive. More research works are involved to minimize the "cell-to-module" (CTM) loss. Our paper is aimed to focus on electrical losses due to interconnection and mismatch loss at PV modules. Research study shows that among all reasons of PV module failure 40.7% fails at interconnection. The mismatch loss in modern PV modules is very low (nearly 0.1%) but still lacks in the approach that determines all the contributing factors in mismatch loss. This review paper is related to study of interconnection loss technologies and key factors contributing to mismatch loss during module fabrication. Also, the improved interconnection technologies, understanding the approaches to mitigate the mismatch loss factors are precisely described here. This research study will give the approach of mitigating the loss and enable improvement in reliability of PV modules.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.7 no.3
• /
• pp.108-117
• /
• 2004

Soil particles from rainfall flow into reservoir and give lots of influence in water quality because the geological conditions and landcover characteristics of Imdong watershed have a weakness against soil loss. Especially, reservoir slant is indicated by the main source area of soil loss. This study selected RUSLE model that could apply GIS and satellite image to evaluate the contribution rate of soil loss in reservoir slant. And we carried out an on-the-spot survey for the range, width and condition of reservoir slant that give much influences to the accuracy of soil loss. As the result of evaluation to the influence of soil loss in reservoir slant, it showed 2.64% in comparison with Imdong watershed. In view of these results, the influence of soil loss in reservoir slant was evaluated in low comparing with Imdong watershed relatively.

• Food Science of Animal Resources
• /
• v.43 no.1
• /
• pp.113-123
• /
• 2023

This study investigated the predictability of cooking loss of pork loin through relatively easy and quick measurable quality properties. The pH, color, moisture, protein content, and cooking loss of 100 pork loins were measured. The explanatory variables included in all linear regression models with an adjust-r² value of ≥0.5 were pH and the protein content. In the linear regression model predicting cooking loss, the highest adjust-r² value was 0.7, with pH, CIE L^*, CIE b^*, moisture, and protein content as the explanatory variables. In 30 pork loins, electrical conductivity was additionally measured, and as a result of linear regression analysis for predicting cooking loss, the highest adjust-r² value was 0.646 with electrical conductivity measured at 40 Hz, with pH and color as the explanatory variables. Ordinal logistic regression analysis was performed to predict the three grades (low, middle, and high) of loin cooking loss using pH, color, and 40 Hz electrical conductivity as the explanatory variables, and the percent concordance was 93.8%. In conclusion, the addition of electrical conductivity as an explanatory variable did not increase the prediction accuracy of the linear regression model for predicting cooking loss; however, it was demonstrated that it is possible to predict and classify the cooking loss grade of pork loin through quality properties that can be measured quickly and easily.