• Asian Journal of Atmospheric Environment
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• 제11권1호
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• pp.33-36
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• 2017

China is suffering from severe air pollution especially fine $PM_{2.5}$ pollution. In 2015, the annual average $PM_{2.5}$ concentration of the 338 municipal cities was $50{\mu}g/m^3$, 78% cities at or above the prefectural level failed to comply with the $PM_{2.5}$ concentration standards. The $13^{th}$ Five-Year Plan for National Economic and Social Development set the goal that the annual average concentration of $PM_{2.5}$ in the municipal cities which failed to attain the ambient air quality standards shall be decreased by 18% by 2020 (CCCPC, 2016). In this study, an air pollution control scenario during the $13^{th}$ Five-Year Plan period was proposed and the $SO_2$, $NO_x$ and PM emission reductions in response to different measures in 31 provincial-level regions mainland China by 2020 were estimated. The air quality in the target year (2020) was simulated using the WRF-CMAQ model. The results showed that by 2020, the emissions of $SO_2$, $NO_x$ and primary PM in mainland China will be reduced by 4.19 million tons, 3.94 million tons and 4.41 million tons, a drop of 23%, 21% and 25% respectively compared with that in 2015, and the annual average concentration of $PM_{2.5}$ will decrease by 19%. Coal-fired power plant contributes the most pollutant emission reduction.

• 한국전자파학회논문지
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• 제18권5호
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• pp.553-562
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• 2007

본 논문에서는 극저주파 자계 세기를 원격으로 측정하기 위한 장치를 설계하고 제작하였다. 자계 측정기는 자계를 등방적으로 측정하기 위하여 3축 자계 센서를 사용하였으며, 측정 대역내 주파수에서 주파수 특성을 보상하기 위하여 등화기를 사용하였다. 3축 자계 센서의 출력 신호를 시간적으로 다중화 시켜, 3축간 균일한 이득 및 주파수 특성을 얻었다. 자계 측정 레벨 범위는 $0.01{\sim}10.0\;uT$이며, 측정 주파수 대역은 $40{\sim}180\;Hz$이 되도록 설계하였다. 제어 시스템은 무선으로 자계 측정기에 접근하며, 최대 접근 거리는 1.0 km이다. 제작된 장치의 측정 레벨 오차는 5% 이내이다. 제작된 장치는 고전압 송전선이 지나는 골프 연습장에 설치되었다.

• 한국정보전자통신기술학회논문지
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• 제5권3호
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• pp.101-109
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• 2012

중위도 지역에서는 위성통신용 파라볼라 안테나를 45도 정도로 기울여 설치해야 된다는 문제점 때문에 이를 대치하기 위한 평면형 안테나의 연구가 활발하게 진행되고 있다. 특히, Ka band를 이용한 위성통신이 활발해지면서 VSAT 용 평면형 안테나의 개발 필요성이 대두되고 있다. 본 논문에서는 평면 안테나 상태로 45도 빔틸트 특성을 갖고, Ka 밴드의 위성통신용으로 30GHz 대역에서 충분한 고이득을 얻기 위해, 빔폭이 좁고 사이드로브가 적으며 저손실 구조의 평면배열 안테나를 설계하였다. 이러한 성능을 만족시키기 위해, 진행파형 누설파 모드를 기초로 한 수직편파 도파관 종방향 슬롯 배열안테나를 제안하였으며, 특히 슬롯 배열들 각각의 폭을 조절하여 복사 전력을 제어함으로써 복사 패턴의 사이드로브 레벨을 저감시켰다. 32개 누설파 소자의 배열안테나 이득은 35.16 dBi 였으며, 빔폭은 2.5도, 사이드로브 레벨은 -30 dB 이하, 중심주파수 30.0 GHz 에서 빔틸트 각도는 45도를 얻었다.

• 한국정보전자통신기술학회논문지
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• 제2권2호
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• pp.69-77
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• 2009

위성방송수신 및 위성 양방향 인터넷, VSAT 등의 위성통신서비스를 차량 이동시에도 이용할 수 있기 위해서는 차량에 탑재하기 용이하도록 소형이며 높이가 낮은 안테나 구조가 요구된다. 또한 중위도 지역에서 평면 안테나 상태로 45도 빔틸트 특성을 갖고, Ka 밴드의 위성통신용으로 충분한 고이득을 얻기 위해, 빔폭이 좁고 사이드로브가 적으며 저손실 구조의 배열안테나 개발이 필요하다. 본 논문에서는 이러한 성능을 만족시키기 위해, 진행파형 누설파 모드를 기초로 한 도파관 종방향 슬롯 배열안테나를 제안하였으며, 특히 슬롯 배열들 각각의 폭을 조절하여 복사 전력을 제어함으로써 복사 패턴의 사이드로브 레벨을 저감시켰다. 32개 누설파 소자의 배열안테나 이득은 34 dBi 였으며, 빔폭은 3.6도, 사이드로브 레벨은 -25 dB 이하로 기존의 경우보다 약 8 dB 의 저감 개선효과를 얻었다. 중심주파수 20.0 GHz에서 빔틸트 각도는 43도를 얻었다. 급전선로는 도파관의 코퍼레이트 급전방식으로 설계하여 광대역, 저손실 특성을 얻을 수 있었다.

• 대한임상검사과학회지
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• 제37권3호
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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.

• 드라이브 ㆍ 컨트롤
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• 제13권2호
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• pp.19-25
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• 2016

Recently, drivers have begun to regard comfort in the cabin as one of the most important factors in construction equipment like forklifts. Accordingly, it has become more important to design a forklift cabin with a better sound quality as well as lower sound level, which can make a driver more comfortable. In this paper, the correlation between subjective evaluation and Zwicker's sound quality index was analyzed through a blind test by a few workers in forklifts and other construction equipment in several countries. Correlation analysis showed that Loudness and Sharpness were ranked in sequence, and tendencies were different from country to country. Also, contribution analysis for Loudness and Sharpness using operational transfer path analysis (OTPA), which is widely used in the field of noise, vibration, and harshness (NVH), was performed. However, Loudness and Sharpness cannot be used with OTPA directly because there are no linear relationships between the sources and receivers. In this paper, both are calculated by applying the DIN 45631 method with a contribution rate (%) of 1/3 Octave Sound Pressure Level by OTPA method in addition to considering spectral masking.

• 한국IT서비스학회지
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• 제20권1호
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• pp.29-40
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• 2021

North Korea's science and technology policies are being pursued under strong leadership and control by the central government. In particular, a large part of the research and development of science and technology related to the Fourth Industrial Revolution in North Korea is controlled and absorbed by the defense organizations under the national defense-oriented policy framework, among which North Korea is making national efforts to develop advanced technologies in artificial intelligence and actively utilize them in the military affairs. The future weapon system based on AI will have superior performance and destructive power that is different from modern weapons systems, which is likely to change the paradigm of the future battlefield, so a thorough analysis and prediction of the level of AI militarization technology, the direction of development, and AI-based weapons system in North Korea is needed. In addition, research and development of South Korea's corresponding weapon systems and military science and technology are strongly required as soon as possible. Therefore, in this paper, we will analyze the level of AI technology, the direction of AI militarization, and the AI-based weapons system in North Korea, and discuss the AI military technology and corresponding weapon systems that South Korea military must research and develop to counter the North Korea's. The next study will discuss the analysis of AI militarization technologies not only in North Korea but also in neighboring countries in Northeast Asia such as China and Russia, as well as AI weapon systems by battlefield function, detailed core technologies, and research and development measures.

• Journal of Preventive Medicine and Public Health
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• 제56권6호
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• pp.487-494
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• 2023

Objectives: Community organization is a resident-led movement aimed at creating fundamental social changes in the community by resolving its problems through the organized power of its residents. This study evaluated the effectiveness of health community organization (HCO), Gangwon's Health-Plus community program, implemented from 2013 to 2019 on residents' health behaviors. Methods: This study had a before-and-after design using 2011-2019 Korea Community Health Survey data. To compare the 3-year periods before and after HCO implementation, the study targeted areas where the HCO had been implemented for 4 years or longer. Therefore, a total of 4512 individuals from 11 areas with HCO start years from 2013 to 2016 were included. Complex sample multi-logistic regression analysis adjusting for demographic characteristics (sex, age, residential area, income level, education level, and HCO start year) was conducted. Results: HCO implementation was associated with decreased current smoking (adjusted odds ratio [aOR], 0.73; 95% confidence interval [CI], 0.57 to 0.95) and subjective stress recognition (aOR, 0.79; 95% CI, 0.64 to 0.97). Additionally, the HCO was associated with increased walking exercise practice (aOR, 1.39; 95% CI, 1.13 to 1.71), and attempts to control weight (aOR, 1.36; 95% CI, 1.12 to 1.64). No significant negative changes were observed in other health behavior variables. Conclusions: The HCO seems to have contributed to improving community health indicators. In the future, a follow-up study that analyzes only the effectiveness of the HCO through structured quasi-experimental studies will be needed.

• 농업과학연구
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• 제50권4호
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• pp.603-616
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• 2023

This study was conducted to investigate the productivity, meat quality, blood variables, stress responses, and litter quality of broilers offered feed with different levels of Glycine (Gly) supplementation under heat stress condition. A total of 760 one-day-old Ross 308 broiler males were randomly assigned to one of the four dietary treatment groups: (1) basal diet (control; CON); (2) basal diet + Gly 0.1% (Gly 0.1%); (3) basal diet + Gly 0.2% (Gly 0.2%); and (4) basal diet + Gly 0.3% (Gly 0.3%). The environments for all the treatments groups were maintained according to broiler rearing guidelines from day 1 to day 21, and heat stress condition (32 ± 1℃, 60 ±5%) was created from day 22 to the end. The addition of Gly increased weight gain and affected feed intake (p < 0.05). Gly 0.1% group had higher pH and ferric reducing antioxidant power (FRAP) in the chicken meat and lower heterophil (HE)/lymphocyte (LY) ratio in the blood (p < 0.05). In particular, Gly 0.2% treatment group had lower serum corticosterone level (p < 0.05) than other groups. For jejunum morphology, the addition of Gly 0.2% significantly reduced the depth of the crypts (p < 0.05). However, the addition of Gly did not significantly affect litter quality (p > 0.05). In conclusion, the addition of glycine improved productivity and meat quality, alleviated heat stress, and improved intestinal function. Further studies are needed to determine the optimal level and mechanism of action of the additive when ingested.

• Journal of Preventive Medicine and Public Health
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• 제26권1호
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• pp.20-36
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• 1993

Work-related low back pain is one of the major factors that cause the loss of working power especially in actively working age, therefore controlling the work-related low back pain is one of the major issues in the field of industrial safety and health. This study was performed for detecting the risk factors and proposing the efficient control program of the work-related low back pain. The subjects were male workers employed at the manufacturing industry in Pusan with longer than 6 months' working duration. The data was collected by self-reported questionnaire and interview from May 1 to October 31,1992. The contents of questionnaire were as follows:. the experience of low back pain within the recent one month, general characteristics(age, marital status, education level, religion, regular exercise), physical characteristics(height, weight), employment status(working duration, daily working hours, rest during work, satis(action fur the job), type of work and working environments(posture, forward bending, lifting and movement, satisfaction for table and chair). The result was analyzed for 608 entire respondents by case-control comparative method. The number of cases was 152 with a history of work-related low back pain, so the relative frequency of self-reported work-related low back pain was 25.0%, and the number of controls was 344 without any history of low back pain. As a result, two characteristics of the employment status(working duration, satisfaction fur the job) and all characteristics of type of work and working environments showed a statistical significance between the case and control groups(p<0.01). The Oddb ratios of these variables for Work-related low back pain were calculated. They were 7.88 for the satisfaction fur chair, 7.86 for lifting and movement,3.31 for satisfaction for table, and 2.22 fur bending forward(p<0.01). And for the multivariate logistic regression analysis confirmed that unsatisfaction for table was independent risk factor for Work-related low back pain. In summary, though this study was based upon the self-reported questionnaire and the subjective complaints, the satisfaction for chair, lifting and movement, satisfaction for table, and bending forward concerned with the type of work and working environments were considered as the main factors causing the work-related low back pain, and the work-related low back pain may be preventable by the ergonomic control of these factors.