• Title/Summary/Keyword: Near

Search Result 22,491, Processing Time 0.041 seconds

A Study on the Evaluation Method of Shielding Effectiveness using NFS in Near-Field Tests (근거리장에서 NFS를 사용한 차폐효율 평가방법에 관한 연구)

  • Park, Jungyeol;Song, Inchae;Kim, Boo-Gyoun;Kim, Eun-Ha
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.53 no.8
    • /
    • pp.76-82
    • /
    • 2016
  • In this paper, we evaluated shielding effectiveness (SE) of carbon nanotube (CNT) film using near field scanning (NFS) in near field analysis. We adopted CNT film with deposit carbon density of 5% and thickness of 1mm for evaluation of shielding characteristic. Using a test coupon analogized to an actual IC package, we measured SE according to measuring position and SE according to distances between the CNT film and the test coupon. As a result, the measured SE in the near field varied with frequency. Especially, the measured electric field SE in the center of the test coupon is better than that of the measured edge point of the test coupon where it is affected by fringing effect. The results show that the measured SE in the near field is affected not only by frequency but also by measurement environment such as position and height of the probe and height of shielding film. In conclusion, we should choose proper methods for SE measurement considering interference distance in the electronic control system because there is little correlation between the proposed evaluation method in the near field and ASTM D 4935-10.

Exposure Assessment of PCDD/Fs and Monitoring of Health Effects on Workers and Resident near the Waste Incinerators in Korea (국내 일부 소각장 근로자와 주변지역주민들의 PCDDs/Fs 노출과 건강 영향 평가)

  • Hong, Yun-Chul;Lee, Kwan-Hee;Kwon, Ho-Jang;Jang, Jae-Yeon;Leem, Jong-Han
    • Journal of Preventive Medicine and Public Health
    • /
    • v.36 no.4
    • /
    • pp.314-322
    • /
    • 2003
  • Objectives : In this study, the exposure status of the hazardous substances from incinerators, such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), were studied , and the relationship between the exposure of these hazardous substances and their heath effects on the workers and residents near municipal solid waste (MSW) incinerators and an industrial incinerator investigated. Methods : Between July 2001 and Jure 2002, 13 workers at two MSW incinerators, 16 residents from the area around the two MSW incinerators, 6 residents from the control area, and further 10 residents near an industrial incinerator, estimated to emit higher levels of hazardous substances, were interviewed. Information, including sociodemographic information, personal habits, and work history, detailed gynecologic and other medical history were collected through interviews. Blood samples were also collected from 45 subjects, and analyzed for PCDD/DFs, by high resolution gas chromatography -high resolution mass spectrometry, using the US EPA 1613 method. In addition to the questionnaire survey, urinary concentrations of 8-hydroxydeoxyguanosine (8-OH-dG) and malondialdehyde (MDA) were measured as oxidative injury biomarkers. The urinary concentrations of 8-OH-dG were determined by in vitro ELISA, and the MDA by HPLC, using u adduct with thiobarbituric acid. Results : The PCDD/DFs concentrations in the residents near the industrial incinerator were higher than those in the controls, workers and residents near the MSW incinerators. The average TEQ (Toxic Equivalencies) concentrations of the PCDD/DFs in residents near the industrial incinerator were 53.4pg I-TEQs/g lipid. The estimated daily intakes were within the tolerable daily intake range (1-4 pg I-TEQ/Kg bw/day) suggested by WHO (1997) in only 30% to the people near the industrial incinerator. Animal studies have already shown that even a low body border of PCDD/DFs, such as 10 ng TEQ/kg bw, can cause oxidative damage in laboratory animals. Our study also showed that the same body burden of PCDD/DFs can cause oxidative damage to humans. Conclusions : The exposures to PCDD/DFs and the oxidative stress of residents near the industrial incinerator, were higher than those in the controls, workers and residents near the MSW incinerators. Proper protection strategies against these hazardous chemicals are needed. Because a lower body burden of PCDD/Fs, such as 10ng TEQ/kg bw, can cause oxidative damage, the tolerable daily intake range should be restrictedly limited to 1pg I-TEQ/kg bw/day.

Present Status and Future Improvements in Groundwater Use Near Streams in the Anseongcheon watershed, Korea (하천 인근 지하수 이용 현황 및 관리 개선방향에 관한 연구)

  • Chung, Il-Moon;Hong, Sung Hun;Lee, Jeongwoo;Kim, Min Gyu
    • The Journal of Engineering Geology
    • /
    • v.27 no.4
    • /
    • pp.383-392
    • /
    • 2017
  • Excessive abstraction of groundwater near streams for agricultural, domestic, or industrial use can significantly reduce the streamflow. Therefore, proper management of water resources must involve careful monitoring of groundwater use near streams. This study investigates the current status of groundwater intake plans in the Anseongcheon watershed, Korea, in order to understand the portion of groundwater wells according to distance from the stream and the distribution of wells near the stream. Among all the wells in the watershed, 20.5% were permitted and 31.3% were declared within 300m from the stream. In particular, among the wells located near streams, 11.4% were permitted and 88.6% were declared among the wells near streams. Therefore, the total amount of groundwater pumping rates from the declared wells is much higher than that from the permitted wells near the stream. Under current guidelines, investigations of the impact of groundwater use near a stream on streamflow depletion should only consider wells permitted by groundwater law. However, prudent management should also pay attention to declared wells, given their large number.

Influencing Factors of Near Miss Experience on Medication in Small and Medium-Sized Hospital Nurses (중소병원 간호사의 투약 근접오류경험 영향요인)

  • No, Me-Hee;Chung, Kyung-Hee
    • The Journal of the Korea Contents Association
    • /
    • v.20 no.10
    • /
    • pp.424-435
    • /
    • 2020
  • The study was descriptive survey research for establishment of patient safety culture in small and medium-sized hospitals as providing baseline data of educational program regarding safe medication and prevention of near miss on medication, checking influencing factors of nurses near miss experience on medication in small and medium-sized hospital. The collected data was analyzed by SPSS/WIN 20.0 program to obtain mean, frequency, x2-test, independent t-test, one-way ANOVA, logistic regression. The influencing factors of near miss experience on medication was working department and patient safety culture among general characteristic. The nurses who were working in general ward had lesser chance to experience near miss rather than nurses working in special department (Odds ratio:2.23, 95%, Confidence Interval: 1.07~4.67, p=.032). The 1 point higher in patient safety culture, the lesser chance to experience in near miss (Odds ratio: 2.24, 95% Confidence Interval: 1.02~4.95, p=.045). To sum up the result of this study, nurses working in special department had higher chance to experience near miss rather than nurses working in general wards. The higher patient safety culture awareness was the lower near miss was experienced. Thus, miss surveillance system for improvement of nurses' patient safety culture awareness should be developed. Moreover, educational program for medication considering nurses' career and department' character should be requested with simulation training considering and theory education.

Correlations between Exophthalmetry and Visual Functions (안구돌출도와 시기능의 상관관계 분석)

  • Kim, Guenhei;Noh, Hyeran
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.20 no.3
    • /
    • pp.325-331
    • /
    • 2015
  • Purpose: This study was to find the correlation between exophthalmetry and visual functions. Methods: Exophthalmetry and visual functions of 200 adults without ophthalmophathy and general disease were examined. Exophthalmetry were measured with Hertel's exophthalmometer. Visual functions (myopia, distance exophoria, near exophoria, near point of convergence, near point of accommodation) were measured for three times. Results: The exophthalmetry was $13.59{\pm}1.10mm$. Myopia, distance exophoria, near exophoria, near point convergence, and near point accommodation were measured as $-2.48{\pm}1.91D$, $3.51{\pm}1.78{\Delta}$, $5.73{\pm}2.44{\Delta}$, $9.63{\pm}2.82cm$, and $21.73{\pm}10.28cm$. With increasing exophthalmetry, the unaided visual acuity, myopia and astigmatism were decreased. On the other hand, distance exophoria, distance esophoria, near exophoria, near point of convergence and near point of accommodation were significantly increased, while exophthalmetry was increased. Conclusions: The relationship between visual functions and exophthalmetry were found to be statistically significant. It could be used as the clinical criteria for prescription of binocular inspections.

Performance of a Commercial Scale Radio-frequency/vacuum Dryer Combined with a Mechanical Compressive Load (산업용 규모의 압체고주파진공건조시스템 성능 평가)

  • LEE, Nam-Ho;ZHAO, Xue-Feng;HWANG, Ui-Do;CHANG, Sae-Hwan;SHIN, Ik-Hyun
    • Journal of the Korean Wood Science and Technology
    • /
    • v.37 no.3
    • /
    • pp.192-199
    • /
    • 2009
  • This study was carried out to investigate the performance of a radio-frequency/vacuum dryer combined with a mechanical compressive load (RF/VC) with a scale of about $3m^3$ during drying board of Azobe (Lophira alata) and Korean red pine (Pinus densiflora). The degree of vacuum of the RF/VC system was maintained at 80~105 torr, and wood temperature was increased from $40^{\circ}C$ at the beginning of drying to $60^{\circ}C$ at the end of drying and the radiofrequency generator was operated with schedule of 7 minute-ON and 3 minute-OFF. The wood temperatures near charge plate always remained higher than those of the control during all of the drying stage, whereas the wood temperature near ground plate always remained lower than those of the controlled. As drying time proceeding, the temperature of the wood near ground plate presented lower than those of the control. Whereas the temperature of the wood near charge plate presented higher than those of the controlled. The final average moisture contents of the Azobe boards stacked near the input side of the RF generator showed slightly lower than those near the opposite side. Those of the wood stacked in the layers near the charge plate were lower than those of near the ground plate. The average length of surface checks of the Azobe boards stacked near the charge plate was very slight, whereas that toward the ground plate represented high values. The efficiency of input energy was simliar with the commercial systems.

A Review of Deep Learning-based Trace Interpolation and Extrapolation Techniques for Reconstructing Missing Near Offset Data (가까운 벌림 빠짐 해결을 위한 딥러닝 기반의 트레이스 내삽 및 외삽 기술에 대한 고찰)

  • Jiho Park;Soon Jee Seol;Joongmoo Byun
    • Geophysics and Geophysical Exploration
    • /
    • v.26 no.4
    • /
    • pp.185-198
    • /
    • 2023
  • In marine seismic surveys, the inevitable occurrence of trace gaps in the near offset resulting from geometrical differences between sources and receivers adversely affects subsequent seismic data processing and imaging. The absence of data in the near-offset region hinders accurate seismic imaging. Therefore, reconstructing the missing near-offset information is crucial for mitigating the influence of seismic multiples, particularly in the case of offshore surveys where the impact of multiple reflections is relatively more pronounced. Conventionally, various interpolation methods based on the Radon transform have been proposed to address the issue of the nearoffset data gap. However, these methods have several limitations, leading to the recent emergence of deep-learning (DL)-based approaches as alternatives. In this study, we conducted an in-depth analysis of two representative DL-based studies to scrutinize the challenges that future studies on near-offset interpolation must address. Furthermore, through field data experiments, we precisely analyze the limitations encountered when applying previous DL-based trace interpolation techniques to near-offset situations. Consequently, we suggest that near-offset data gaps must be approached by extrapolation rather than interpolation.