• Title/Summary/Keyword: Extremely low frequency

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Zinc Intake and Status of the Selected Korean Adults

  • Lee, Soo-Lim;Kwak, Eun-Hee;Yoon, Jin-Sook;Kwon, Chong-Suk;Beattie, John H.;Kwun, In-Sook
    • Preventive Nutrition and Food Science
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    • v.9 no.1
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    • pp.79-84
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    • 2004
  • Zinc intake and status of South Koreans from rural, urban and metropolitan areas were investigated. The dietary habits of 760 healthy male and female adult subjects with a mean age of 54 were assessed using a food frequency questionnaire and were verified using 24 h dietary recall. Daily Zn intakes for men and women were 7.4$\pm$5.4 mg and 7.0$\pm$5.4 mg, respectively, which were 62% and 70% of the Korean RDA. The phytate : zinc and phytate ${\times}$ calcium : zinc molar ratios were 38 and 398, respectively. Both the low intake of zinc and the high extremely phytate and phytate ${\times}$ calcium ratios with Zinc suggest that South Koreans may be at risk of zinc deficiency. Plasma zinc (86$\pm$61 $\mu\textrm{g}$/dL), urinary zinc (33$\pm$27 $\mu\textrm{g}$/dL) and plasma alkaline phosphatase (102$\pm$52 mU/mL) levels within the normal range did not however suggest marked Zinc deficiency in these subjects. However, conventional zinc biomarkers aye known to be unreliable for assessment of marginal zinc deficiency. Based on zinc intake alone, it is likely that at least a proportion of these subjects were marginally zinc deficient and the wider consumption of zinc rich, phytate deficient foods, particularly in rural areas, would be beneficial.

Compact Triple-Mode Bandpass Filter Using a Cylindrical Dielectric Resonator (원통형 삼중모드 유전체 공진기를 이용한 대역 통과 여파기의 설계)

  • Jang, Geon-Ho;Park, Nam-Shin;Kim, Byung-Chul;Lee, Don-Yong;Won, Jung-Hee;Wang, Xu-Guang
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.1
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    • pp.30-38
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    • 2015
  • In this paper, the design of a compact triple-mode bandpass filter using a high-Q cylindrical dielectric resonator is proposed. In detail, the triple $TE_{01{\delta}}$ modes along three orthogonal axes are used and novel coupling structure in the metallic enclosure is adopted to introduce the coupling between the resonant modes. Due to the cross coupling, the proposed bandpass filter has an asymmetric frequency response with flexible three transmission zeros, one of which can be located very close to the passband edge to provide an extremely sharp skirt characteristic with low insertion loss. The proposed filter is about 60 % miniaturized compared with conventional single-mode dielectric resonator filter. The proposed bandpass filter design is validated by the circuit and 3D EM simulations and measurements compared to the target specifications.

Anthropometic Characteristics, Serum Profiles, Health Status, Food Intakes Frequency and Nutrient Intakes by Married Status of Men Aged 30-39 - Based on Korean National Health and Nutrition Examination Survey (2008-2015) - (30대 남성의 결혼 여부에 따른 신체계측, 혈액성상, 건강상태, 식품섭취빈도 및 영양소 섭취량 비교 - 국민건강영양조사(2008~2015년)에 기초하여 -)

  • Choi, Soon Nam;Jho, Kwang Hyun;Chung, Nam Yong
    • 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.

An Analysis of User Satisfaction of K University's Library Service

  • Noh, Young-Hee;Choi, Min-Ju;Choi, Yong-Wog;Jeong, Sin-Won;Jung, Eun-Ji;Kang, Mi-So;Kim, Jin-Young;Lee, Kyung-Won;Lee, Sung-Jae;Oh, Seon-Hye;Park, So-Yeon;Shin, Sung-Chul;Suh, Da-Jeong
    • 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.

Anthropometic Characteristics, Serum Profiles and Nutrient Intakes by Drinking and Non-Drinking Status of Korean Women Aged 30-49 Years - Based on Korean National Health and Nutrition Examination Survey (2008-2015) - (30~40대 여성의 음주 여부에 따른 신체적 특징, 혈액성상, 영양소 섭취량 비교 - 국민건강영양조사(2008~2015년)에 기초하여 -)

  • Choi, Soon Nam;Jho, Kwang Hyun;Chung, Nam Yong
    • Journal of the Korean Dietetic Association
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    • v.24 no.1
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    • pp.48-61
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    • 2018
  • This study was conducted to investigate the anthropometric data, serum profiles, food intakes frequency, and nutrient intakes of women aged 30-49 years. The subjects were divided into two groups: drinking group and non-drinking group. For the study, we obtained data for analysis from the combined 2008-2015 Korean National Health and Nutrition Examination Survey (KNHANES). Height and weight were 159.2 cm and 58.1 kg in the drinking group as well as 158.1 cm and 57.7 kg in the non-drinking group, respectively. Obesity percentage in the two groups were 22.5% and 24.8%, respectively. HDL-cholesterol (P<0.001) and Vitamin D (P=0.0248) levels in the drinking group were significantly higher than those of the non-drinking group. In the drinking group, rates of hypertension, myocardial infarction, and diabetes were significantly lower than those of the non-drinking group. Food and nutrient intakes, including energy, water, protein, fat, retinol, thiamin, riboflavin, and niacin, in the drinking group were significantly higher than those of the non-drinking group. In the two groups, energy, water, fiber, calcium, and potassium intakes were low while Na intakes were extremely high considering KDRIs (Dietary Reference Intakes for Koreans). The mean adequacy ratio (MAR) in the two groups was not significant.

Analysis of ELF Magnetic Field Reduction Factor of Electric Power Transmission Line (송전 선로 극저주파 자기장 저감지수(FRF) 특성 해석)

  • Myung, Sung-Ho;Cho, Yeon-Gyu;Lee, Dong-Il;Lim, Yun-Seok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.11 s.114
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    • pp.1132-1142
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    • 2006
  • This paper examined electric power transmission line models of reducing ELF(Extremely Low Frequency) magnetic field and analyzed the effects about models. In this research, FRF(Field Reduction Factor) of various models reducing magnetic field were analyzed compared to the horizontal 154 kV transmission line. As a result, the reduction ratio of magnetic field was almost proportioned to the compaction of phase-to-phase distance, and in case of diamond model and transposed model, magnetic field was able to be reduced nearly 50 %. It was analyzed that the magnetic field reduction ratio of triangle model was about 33 % and the magnetic field reduction ratio of split model was able to be reduced to 50 %. Especially, the magnetic field reduction ratio of multi split model could be reduced to 80 %.

A Study on the Technical Regulation of Weak Electric Filed Strength Radio Equipment about 8.2Hz Frequency Band (8.2MHz 대역 미약 전계강도 무선기기의 출력기준에 관한 연구)

  • Kim, Sun-Youb;Ra, Yoo-Chan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.12
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    • pp.2498-2504
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    • 2009
  • This paper compared the output limit value of the Korean weak electric field strength wireless device in the 8.2MHz band with the standard values of foreign countries. Through this, the study confirmed that the Korean regulation was lower by about 10-20dB than those of the USA or Europe. In order to prove this, the study measured outputs by entrusting the 8.2MHz EAS system to two measuring companies. As a result of these measurements, electric field strengths were shown to be $70.6dB{\mu}V/m$ and $68.3dB{\mu}V/m$ respectively, and these values were confirmed to exceed the current Korean standard of $59.8dB{\mu}V/m$. Accordingly, it is deemed necessary to review the specifications of the Korean standard in the 8.2MHz band.

Intracellular $Ca^{2+}$ Mobilization and Beta-hexosaminidase Release Are Not Influenced by 60 Hz-electromagnetic Fields (EMF) in RBL 2H3 Cells

  • Hwang, Yeon-Hee;Song, Ho-Sun;Kim, Hee-Rae;Ko, Myoung-Soo;Jeong, Jae-Min;Kim, Yong-Ho;Ryu, Jeong-Soo;Sohn, Uy-Dong;Gimm, Yoon-Myoung;Myung, Sung-Ho;Sim, Sang-Soo
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.5
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    • pp.313-317
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    • 2011
  • The effects of extremely low frequency electromagnetic fields (EMF) on intracellular $Ca^{2+}$ mobilization and cellular function in RBL 2H3 cells were investigated. Exposure to EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h did not produce any cytotoxic effects in RBL 2H3 cells. Melittin, ionomycin and thapsigargin each dose-dependently increased the intracellular $Ca^{2+}$ concentration. The increase of intracellular $Ca^{2+}$ induced by these three agents was not affected by exposure to EMF (60 Hz, 1 mT) for 4 or 16 h in RBL 2H3 cells. To investigate the effect of EMF on exocytosis, we measured beta-hexosaminidase release in RBL 2H3 cells. Basal release of beta-hexosaminidase was $12.3{\pm}2.3%$ in RBL 2H3 cells. Exposure to EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h did not affect the basal or $1{\mu}m$ melittin-induced beta-hexosaminidase release in RBL 2H3 cells. This study suggests that exposure to EMF (60 Hz, 0.1 or 1 mT), which is the limit of occupational exposure, has no influence on intracellular $Ca^{2+}$ mobilization and cellular function in RBL 2H3 cells.

Health Status of Electric Utility Workers Exposed to Extremely Low Frequency Electromagnetic Field (ELF-EMF) (근로자들의 극저주파 전자파 노출 수준에 따른 인체 영향 평가)

  • Park, Kyoung-Ho;Ahn, Yong-Ho;Kim, Tai-Jeon
    • Korean Journal of Clinical Laboratory Science
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    • v.37 no.3
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    • pp.220-227
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    • 2005
  • Recently, the use of an electrical apparatus has brought up concerns of health risks from exposure to electromagnetic fields. EMF is composed of electric fields and magnetic fields. Heavy exposure to EMF can occur only in the vicinity of high-voltage overhead transmission lines, close to transformers and underground cables, and also close to large electrical machinery. In this thesis I have investigated the hypothesis of the correlation between occupational exposure to ELF-EMF and the risks of leukemia, anemia, cancer. Therefore, the aim of this study is to investigate whether or not ELF-EMF emitted from electric power stations and transformer substations affect some hematological parameters and tumor markers of electric utility workers. The hematological test results and tumor markers under investigation were similar in the two groups but some of parameters such as RBC, AFP, LDH showed significant difference between the two groups from two sample t-test (p<0.05). The exposure group showed increased LDH level compared to the control group by two sample t-tests. In addition, the abnormal LDH level in the exposure group was observed to be clinically significant by ${\chi}^2$-test. However, the levels of RBC, AFP observed were not clinically significant by ${\chi}^2$-test (p>0.05). These results suggested that ELF-EMF does not affect most blood test parameters except LDH of electric utility workers.

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A Study on the Technical Regulation of Weak Electric Filed Strength Radio Equipment about 58kHz Frequency Band (58kHz 대역 미약 전계강도 무선기기 기술 기준에 관한 연구)

  • Park, Hyoung-Keun;Kim, Sun-Youb;Ra, Yoo-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.9
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    • pp.2319-2325
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    • 2009
  • This paper compared the output limits value of the Korean weak electric field strength wireless device in the 58kHz band with the standard values of foreign countries. Through this, the study confirmed that the Korean regulation was lower by about 50dB than those of the USA or Europe. In order to prove this, the study measured outputs by entrusting the 58kHz EAS system to two measuring companies. As a result of these measurements, electric field strengths were shown to be $112dB{\mu}V/m$ and $08dB{\mu}V/m$ respectively, and these values were confirmed to exceed the current Korean standard of $102.7dB{\mu}V/m$. Accordingly, it is deemed necessary to review the specifications of the Korean standard in the 58kHz band.