• Journal of the Korean Society of Physical Medicine
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• v.9 no.4
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• pp.415-424
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• 2014

PURPOSE: This study examined the effect of high-frequency transcutaneous electrical nerve stimulation (TENS) and San-Yin-Jiao (SP6) acupressure on primary dysmenorrhea. Furthermore, the difference in effectiveness between the two methods were compared. METHODS: Twenty-six students participated in this study, and were randomly assigned to a high-frequency TENS group(experimental 1, n=9), a San-Yin-Jiao (SP6) acupressure group(experimental 2, n=9), and no treatment group(control, n=8). They were assessed and treated on the first day of their menstruation. The TENS protocol included applying 20 minutes of stimulation with a frequency of 100Hz, $100{\mu}sec$ pulse width. Four electrodes were placed on the skin 3 cm from midline at T12-L1 and S2-3 paravertebral muscles. San-Yin-Jiao (SP6) acupressure should be applied with the thumb for 10 minutes(8 seconds pressure and 2 seconds rest) on the SP6 acupoint. This procedure should be repeated for the other foot. Dysmenorrheal pain measured two pain assessment tools (VAS, DPT) pre-treatment; immediate post-treatment; 30minutes, 1, 2hours; and 3, 4, 5, 6, 24 hours after the VAS test were added. RESULTS: The results showed significant differences in pain assessments (VAS, DPT) after treatment for subjects of experimental group1 (p<.05) and experimental group2 (p<.05), whereas the between-group comparison found no statistically significant differences. CONCLUSION: This result supports the idea that using two methods could be effective in pain reduction among students who suffered from primary dysmenorrhea.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.3
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• pp.100-111
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• 2009

Cognitive radio is an advanced technology for efficient utilization of under-utilized spectrum via spectrum sensing. CR users should move from current allocating channel to empty channel to avoid the interference to the primary user if the primary user is allocating that channel. Thus, CR system cannot support the CR user's QoS(Quaiity of Service). In this paper, we propose dynamic frequency selection method based on Genetic Algorithm with power control. It is to find the optimization channel for satisfying various CR user's needs with the power control method to minimize the CR user's interference to the primary user. And, we propose the Genetic Algorithm(GA) which determines the best configuration for CR communication systems. The computer simulation results show that the proposed method guaranteed the primary user's decodability and the optimized solution for various channel status.

• Smart Structures and Systems
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• v.25 no.1
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• pp.65-80
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• 2020

In order to protect a structure over its full life cycle, a novel tuned mass damper (TMD), the so-called semi-active eddy current pendulum tuned mass damper (SAEC-PTMD), which can retune its frequency and damping ratio in real-time, is proposed in this study. The structural instantaneous frequency is identified through a Hilbert-Huang transformation (HHT), and the SAEC-PTMD pendulum is adjusted through an HHT-based control algorithm. The eddy current damping parameters are discussed, and the relationship between effective damping coefficients and air gaps is fitted through a polynomial function. The semi-active eddy current damping can be adjusted in real-time by adjusting the air gap based on the linear-quadratic-Gaussian (LQG)-based control algorithm. To verify the vibration control effect of the SAEC-PTMD, an idealized linear primary structure equipped with an SAEC-PTMD excited by harmonic excitations and near-fault pulse-like earthquake excitations is proposed as one of the two case studies. Under strong earthquakes, structures may go into the nonlinear state, while the Bouc-Wen model has a wild application in simulating the hysteretic characteristic. Therefore, in the other case study, a nonlinear primary structure based on the Bouc-Wen model is proposed. An optimal passive TMD is used for comparison and the detuning effect, which results from the cumulative damage to primary structures, is considered. The maximum and root-mean-square (RMS) values of structural acceleration and displacement time history response, structural acceleration, and displacement response spectra are used as evaluation indices. Power analyses for one earthquake excitation are presented as an example to further study the energy dissipation effect of an SAECPTMD. The results indicate that an SAEC-PTMD performs better than an optimized passive TMD, both before and after damage occurs to the primary structure.

• Korean Journal of Community Nutrition
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• v.19 no.3
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• pp.223-230
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• 2014

Objectives: The purpose of this study was to provide the preliminary data for dietary education to increase students' vegetables intake. Methods: The attitude of vegetables consumption (5-Likert scale), preference score (7-Likert scale) and eating frequency (5-Likert scale) of 9 fragrance vegetables were investigated by survey questionnaire. A total of 370 students enrolled in primary, middle, high schools, and university participated in the study and data were analyzed by the SPSS WIN (ver 12.0). Results: About 40% of those surveyed answered that they do not eat some kinds of foods and 16% of students do not eat vegetables, the most unfavorable foods. The students in all groups (primary $2^{nd}$ and $2^{th}$, middle and high school, university students) answered that they liked vegetables with the highest score in university students, and they did not often eat fragrance vegetables. Lower age student group, especially primary school $2^{nd}$ showed more positive attitudes of eating challenge toward no experience, bad taste, and dislike but nutritious vegetable foods. The most important factor of vegetable preference was taste, the biggest reason of both like and dislike. Only 4 students designated nutrition as for vegetable dislike reason, means that all students knew about the nutritional importance of vegetables. It was shown that the color and flavor of the vegetables act as dislikable reason rather than likable reason. The significant correlations between preference score and intake frequency of fragrance vegetables were confirmed, and the younger the students the greater the correlation coefficient. Conclusions: Thus providing more chance to experience vegetables, such as fragrance vegetables and education about the importance of balanced diet will be an effective way of increasing vegetables intake, and the younger the students the greater the education effect.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.493-501
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• 2022

Objective: The purpose of this study is to present basic data for appropriate therapeutic intervention by confirming changes in the autonomic nervous system and pain by applying high-frequency deep diathermy to the lower abdomen in patients with primary dysmenorrhea. Design: A randomized controlled clinical trial. Methods: Thirty-eight women aged 18-50 years who complained of regular menstrual cycles (24-32 days) and primary dysmenorrhea symptoms were randomly assigned to a high-frequency therapy group (5, 7, or 9 mins) and a superficial heat therapy group (20 min). High frequency treatment group: The subject was in a supine position, and radio frequency was applied to the lower abdomen below the umbilicus. The radio frequency therapy device used in this study uses a 300 kHz capacitive electrode and a 500 kHz resistive electric transfer to deliver deep heat. Superficial heat treatment Group: Subjects applied a hot pack to the lower abdomen for 20 minutes while lying on their back. Evaluations were made of Heart rate variability and Visual Analogue Scale. Results: In subjects with menstrual pain, there was a significant difference in pain between the high-frequency therapy group and the superficial heat therapy group (p=0.026). However, there was no significant difference between the autonomic nervous system and the stress resistance (p>0.05). Conclusions: As a result of this study, high-frequencytreatment using radiofrequency was effective in relieving pain because it can penetrate deeper tissues than conventional hot packs using superficial heat. In particular, it was found that the optimum effect was obtained when high frequency was applied forfive-seven minutes.

• Journal of Korea Multimedia Society
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• v.14 no.12
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• pp.1549-1558
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• 2011

In this paper, we address the problem of bandwidth sharing among multiple primary users and multiple secondary users in a cognitive radio network. In cognitive radio networks, effective spectrum assignment for primary and secondary users is a challenge due to the available broad range of radio frequency spectrum as well as the requisition of harmonious coexistence of both users. To handle this problem, firstly, Bertrand game model is used to analyze a spectrum pricing in which multiple primary users emulate with each other to acquire maximal profit. After that, we employ Cournot game to model the spectrum sharing of secondary users to obtain optimal profit for each user also. Simulation results show that our scheme obtains optimal solution at Nash equilibrium.

• Journal of the Korean Institute of Educational Facilities
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• v.12 no.2
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• pp.14-22
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• 2005

This study analyzed the remodeling cases of 53 public primary schools located in Seoul to grasp the trends and set the direction in remodeling public primary schools. As a result of the analysis, before the sixth Education Process major remodeling of schools was focused on increasing the number of classrooms and after the sixth Education Process public space was increased. According to development of education, frequency of remodeling is increased. But myopic remodeling works were not a surprise. It means the schools simply focused on increasing space. Therefore, the study aims to set the direction for a comprehensive and systemic remodeling plan which will serve as an opportunity to not only improve physical life of schools but also extend functional life and enhance the quality of educational environment.

• The Journal of the Korean dental association
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• v.11 no.5
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• pp.313-316
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• 1973

970 children visited attached hospital, S.N.U, were taken orthopantomograph. Of those children, there were 14 patients who have primary fused teeth. The author observed those cases and got following results. 1) Incidence of primary fused teeth was higher in female. 2) In the order of frequency, fused teeth of mandibular right primary lateral incisor and canine were 9 and that of mandibular left primary lateral incisor and canine were 4, and there was only one case in maxillary. 3) 13 cases showed the congenital absence of lateral incisor of the corresponding permanent teeth. 4) Incidence of fused teeth was 1.44%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.7
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• pp.978-983
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• 2015

This paper presents Frequency Bias setting for the adequate AGC(Automatic Generator Control) operation based on the frequency response of power system in Korea. AGC frequency control recovers the frequency up to 60Hz following a primary control when the frequency suddenly drops due to a fault in power system. AGC can compensate an appropriate amount of generation by calculating ACE(Are Control Error) from the frequency deviation with the AGC frequency bias set from the actual frequency response in power systems. An appropriateness of the proposed AGC bias setting is verified through case studies employing the simulation model.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1621-1628
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• 2016

Experiencing power declines when the secondary coil is at the middle position between two primary coils is a serious problem in segmented on-road charging systems with a single energized segmented primary coil. In this paper, the topological transformation of a primary circuit and a hierarchical compensation capacitor control are proposed. Firstly, the corresponding compensation capacitors and receiving powers of different primary structures are deduced under the condition of a fixed frequency. Then the receiving power characteristics as a function of the position variations in systems with a single energized segmented primary coil and those with double segmented primary coils are analyzed comparatively. A topological transformation of the primary circuit and hierarchical compensation capacitor control are further introduced to solve the foregoing problem. Finally, an experimental prototype with the proposed topological transformation and hierarchical compensation capacitor control is carried out. Measured results show that the receiving power is a lot more stable in the movement of the secondary coil. It is a remarkable fact that the receiving power rises from 10.8W to 19.2W at the middle position between the two primary coils. The experimental are in agreement with the theoretical analysis.