• Journal of Power Electronics
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• v.16 no.3
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• pp.1110-1121
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• 2016

The mathematical model of a three phase PWM converter under the stationary αβ reference frame is deduced and constructed based on a Proportional-Resonant (PR) regulator, which can replace trigonometric function calculation, Park transformation, real-time detection of a Phase Locked Loop and feed-forward decoupling with the proposed accurate calculation of the inductance voltage vector. To avoid the parallel resonance of the LCL topology, the active damping method of the proportional capacitor-current feedback is employed. As to current vector error elimination, an optimized PR controller of the inner current loop is proposed with the zero-pole matching (ZPM) and cancellation method to configure the regulator. The impacts on system's characteristics and stability margin caused by the PR controller and control parameter variations in the inner-current loop are analyzed, and the correlations among active damping feedback coefficient, sampling and transport delay, and system robustness have been established. An equivalent model of the inner current loop is studied via the pole-zero locus along with the pole placement method and frequency response characteristics. Then, the parameter values of the control system are chosen according to their decisive roles and performance indicators. Finally, simulation and experimental results obtained while adopting the proposed method illustrated its feasibility and effectiveness, and the inner current loop achieved zero static error tracking with a good dynamic response and steady-state performance.

• Journal of the Korean Dietetic Association
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• v.22 no.3
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• pp.193-213
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• 2016

The purpose of this study is to provide a standard job description for a nutrition teacher placed in primary and secondary schools by analyzing their duties. DACUM is an acronym for 'Developing A CUrriculuM'. It was used by experts to determine the job duties, tasks and task elements to establish the job descriptions of a nutrition teachers through the development of a DACUM chart. An expert panel consisting of 10 nutrition teachers participated in a DACUM workshop and derived nutrition teacher's DACUM chart. A total of 1,550 nutrition teachers across the country were targeted as the survey subjects for validation of the DACUM chart through their perception of the frequency, importance, and difficulty of each item in the job description. A tree structure, criticality analysis, and contents validity index were added for verification. The definition of the nutrition teacher's job and DACUM chart with 5 duties, 28 tasks, and 107 task elements were derived by the DACUM method. The definition of a nutrition teacher was 'A teacher who is responsible for food service management and nutrition education and counseling for health promotion and disease prevention for students in primary and secondary schools'. The validation results of the tree structure were the priorities of the 28 tasks with ranks 1 and 2. Because there was no third priority, it was considered to be a good representation of the tasks of nutrition teachers. The DACUM chart was found to be evenly distributed with relative importances of more than 17 or less than 11 through the criticality analysis. Since the C5-4 (Conduct simulation exercise against food poisoning)'s content validity index was significantly less than the reference value of 0.78, it was not included in the final job description. 5 duties, 28 tasks, 102 task elements were included in the final job description of a nutrition teacher.

• Journal of the Korean Dietetic Association
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• v.23 no.3
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• pp.223-239
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• 2017

This study was conducted to investigate the anthropometric data, serum profiles, nutrient intakes and diet quality of men in their 30s. The subjects were divided into a married group and an unmarried group. For the study, we obtained data for analysis from the combined 2008~2015 Korean National Health and Nutrition Examination Survey (KNHANES). Mean height and weight of study population were 173.5 cm, and 74.0 kg in the married group and 173.1 cm, and 73.6 kg in the unmarried group, respectively. Systolic blood pressure in the unmarried group was significantly higher than that of the married group (P<0.001), while circulating vitamin D levels in the married group were significantly higher than those of the unmarried group (P<0.001). The proportion of obesity in the two groups was 42.41% and 38.40%, respectively. In the unmarried group, prevalence of depression was significantly higher than that those of the married group. Intakes of energy, water, protein, fat, carbohydrate and calcium in the married group were significantly higher than those of the unmarried group. In both groups, water and fiber intakes were low and sodium intakes were extremely high based on the KDRIs (Dietary Reference Intakes for Koreans). The mean adequacy ratio (MAR) of the married group was higher than that of the unmarried group. The index of nutritional quality (INQ) in the married group was also higher than that of the unmarried group. Therefore, we propose development of dietary guidelines and education programs for improvement of food and nutrient intakes, nutrition balance and dietary quality of unmarried men in their 30s.

• Journal of East-West Nursing Research
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• v.8 no.1
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• pp.135-146
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• 2003

Moxibustion plays an important role not only in the medical service, but also in the health care of Korea. So this study attempted to review of moxibustion and analyze of domestic study trend. And it also intends to examine the usefulness of moxibustion treatment in Korean nursing intervention. "Donguibogam" is famous for the most comprehensive medical book in ancient Korea, indicates that moxibustion makes up a large part of it and that its contents were composed of material, size, time, caring of one's health, indication, operational procedure, contraindication in the documented in the 25 reference books. Also, It confirms that it has been widely used since old times. Especially, it seems to be a great help to researchers because its content lay a theoretical foundation. From the literature, we identified that moxibustion was most widely using method for health promotion and an efficacious cure for a disease. I searched and investigated the journals and dissertations supplied by KERIS and RICH with the key word "moxibustion". Of 10 articles with moxibustion intervention, the trend of domestic studies shows, that of an area relating to nursing was 5. Therefore, moxibustion intervention steadily increases in frequency in nursing academic circles year by year. But there is no distinction between hand moxibustion and moxibustion. According to the above results, we need to develop moxibustion learning program and well designed experimental study with moxibustion for Korean Nursing intervention.

• Journal of Korean Clinical Health Science
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• v.4 no.4
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• pp.680-688
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• 2016

Purpose. This study aims to explore Situations and Problems of the Community Senior Citizen Center as the senior health care and the Elderly's Leisure status. Then, aims to arrange Activation Vitalization Plan of the senior's leisure in Community Senior Citizen Center. Methods. The literature and data used in this study was based on a questionnaire survey, mostly from Gyeongki-Do Community Senior Citizen Center Branch and statistical research data. Literature review and analysis frequency was by reference to the paperback and academic papers related to the senior health welfare. Results. First, the period of the seniors with the Community Senior Citizen Center as health facilities has appeared in 6-10years(32.8%), followed by the response showing that more than 10years(32.4%). Therefore, it reveals that the senior live in the same region in the long term. Second, the number of days that the senior health care the Community Senior Citizen Center has been used by the senior was over 5days. This result was supported by 608people(61.7%). Both men and women replied that they use the health center more than five days. Third, the number of the senior who responded that they use the Community Senior Citizen Center as health facilities 629people(63.9%). They replied that they use the facilities mostly afternoon. The senior use the facilities all day appeared to 263people(26.7%). Conclusions. It seems like that there needs to be a variety of personalized programs that can be added to increase the life satisfaction of the senior participation in leisure programs for the Community Senior Citizen Center as senior health facilities in the future. Additionally, the government needs to require a wide range of financial support for the Community Senior Citizen Center as senior health care and devise the strategies that will lead the health center for the senior need to be actively utilized.

• The Korean Journal of Community Living Science
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• v.22 no.4
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• pp.509-518
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• 2011

This study was intended to investigate dietary behavior, health related behavior and the effects of nutrient intake of female college students. Dietary behavior, health related behavior and the perception of the body conditions were surveyed with anonymous questionnaires, and 24hrs recall method for nutrient intake was obtained from 161 female college students in Chungbuk area. The mean height and weight of the subjects were $161.4{\pm}5.0$cm and $53.8{\pm}7.4 $kg, respectively. The dietary behavior of female college students was generally inadequate. More specifically, irregularity of meals, indifference of dietary balance, and skipping breakfast, showing $4.77{\pm}2.20$for dietary behavior score, $11.76{\pm}3.89$ for DVS and $3.58{\pm}0.82$ for DDS, respectively. It was found that almost 63% of subjects did not anything for health care and the frequency of exercise of subjects was low. The perception of body conditions of the subjects seemed to be generally positive. However, satisfaction levels on body shape was very negative showing that only 12.4% of subjects answered as 'very satisfied' and 'satisfied'. When nutrient intake of the female college students was compared with Dietary Reference Intake for Korean, folate(45%), potassium(55%), vitamin C(59%), Ca(72%), fiber(72%), Fe(79%) and energy(80%) were found to be insufficient. But protein(138%), P(122%) and Na(179%) were found to be oversupplied. The nutrient intake of fiber, plant Ca, vitamin A, ${\beta}$-carotene, vitamin B6, vitamin C, folate and vitamin E were significantly higher, and those of Fe, Zn and protein were a little high in the high score group of dietary behavior. Also Food group intake, DDS and DVS were higher in the high score group of dietary behavior.

• Wind and Structures
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• v.17 no.1
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• pp.43-68
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• 2013

The fluctuating wind induced vibration is one of the most important factors which has been taken into account in the design of long-span bridge due to the low stiffness and low natural frequency. Field measurement characteristics of sustained wind on structure site can provide accurate wind load parameters for wind field simulation and structural wind resistance design. As a suspension bridge with 1490 m main span, the Runyang Suspension Bridge (RSB) has high sensitivity to fluctuating wind. The simultaneous and continuously wind environment field measurement both in mid-span and on tower top is executed from 2005 up to now by the structural health monitoring system installed on this bridge. Based on the recorded data, the wind characteristic parameters, including mean wind speed, wind direction, the turbulence intensity, the gust factors, the turbulence integral length, power spectrum and spatial correlation, are analyzed in detail and the coherence functions of those parameters are evaluated using statistical method in this paper. The results indicate that, the turbulence component of sustain wind is larger than extremely strong winds although its mean wind speed is smaller; the correlation between turbulence parameters is obvious; the power spectrum is special and not accord with the Simiu spectrum and von Karman spectrum. Results obtained in this study can be used to evaluate the long term reliability of the Runyang Suspension Bridge and provide reference values for wind resistant design of other structures in this region.

• International Journal of Knowledge Content Development & Technology
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• v.1 no.1
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• pp.61-79
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• 2011

This study purposed to discover whether or not academic libraries reflect these changing roles. We selected K University as the research target and surveyed user satisfaction of materials, staff services, facilities, electronic devices, media, and so on. The research findings are as follows: 1) the frequency of library visits of University K was on the high side, 2) the primary purpose of using the academic library was associated with learning or reading, therefore, the most used library spaces were related to that, 3) the most used library materials were 'general books', the most unused were 'reference books', 4) the most preferred way to obtain needed materials when failing to find wanted materials was 'Contact librarian'. A similar phenomenon occurred in terms of facility use, 5) university K's users were usually satisfied with the loan policy, 6) the rate of users who don't know whether there is user education was very high, the rate of users who have no experience with user education was extremely low. These research findings can be referenced by library management to improve libraries' service quality and take advantage of complex spatial configurations.

• Journal of Semiconductor Engineering
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• v.1 no.1
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• pp.13-30
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• 2020

Radio frequency (RF) energy harvesting technology have become a reliable and promising alternative to extend the lifetime of power-constrained wireless networks by eliminating the need for batteries. This emerging technology enables the low-power wireless devices to be self-sustaining and eco-friendly by scavenging RF energy from ambient environment or dedicated energy sources. These attributes make RF energy harvesting technology feasible and attractive to an extended range of applications. However, despite being the most reliable energy harvesting technology, there are several challenges (especially power conversion efficiency, output DC voltage and sensitivity) poised for the implementation of RF energy harvesting systems. In this article, a detailed literature on RF energy harvesting technology has been surveyed to provide guidance for RF energy harvesters design. Since signal strength of the received RF power is limited and weak, high efficiency state-of-the-art RF energy harvesters are required to design for providing sufficient DC supply voltage to wireless networks. Therefore, various designs and their trade-offs with comprehensive analysis for RF energy harvesters have been discussed. This paper can serve as a good reference for the researchers to catch new research topics in the field of RF energy harvesting.

• Journal of the Korean Dietetic Association
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• v.18 no.4
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• pp.283-296
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• 2012

As a disease that reduces quality of life, functional dyspepsia (FD) is associated with foods that may worsen its symptoms or cause it. The purpose of this study was to examine the nutritional status and dietary behaviors of FD patients. We investigated food intake, food intake frequency, and dietary habits of 45 FD subjects according to the Rome III Diagnosis Criteria. Average age and body mass index (BMI) were 47.7 years and $22.6kg/m^2$ (males: $23.4kg/m^2$, females: $22.1kg/m^2$), respectively. Average energy intake was 77% of Korean Dietary Reference Intake (KDRI), and it was less than that of the Korea National Health and Nutrition Examination Surveys (KNHANES). Other nutrient intake levels were similar to the KNHANES. Energy intake proportion of carbohydrates : protein : fat was 56 : 18 : 26, and the ratio of fat intake was higher than that of the KNHANES. Beans, laver, tomato, and yogurt were consumed very frequently. In the results of meal regularity, dietary behaviors and composition of diet were relatively good. It is likely that the patient controlled their diet by eating cautiously and by reducing alcohol drinking and smoking. Our results indicate that FD patients' nutritional status by consumption of nutrients was at a level of normal healthy people and that dietary habits were better than normal adults. However, their fat intake levels were somewhat higher than normal people. Therefore, further research is required to identify the relationship between dietary intakes and FD.