• Title/Summary/Keyword: induced current measurement system

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Myth of 61.8% rule and the practical application notices (접지저항 측정의 61.8%법칙 적용의 맹점과 현실적 접근 방법)

  • Lee, Sang-Mu;Cho, Pyung-Dong
    • 한국정보통신설비학회:학술대회논문집
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    • 2005.08a
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    • pp.259-262
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    • 2005
  • Ground resistance measurement is an elementary technique for the evaluation of grounding system. There are main environmental factors to consider for correct measurement but the problem is that it is practically most cases to measure ground resistance unable to know the factors. This paper presents a methodology toward true value of resistance in the unknown circumstances, utilizing the defined term 'variation rate' of potential difference curve appearing in the distance to a current probe as in the three point fall-of-potential method which comprises the characteristics of environmental factors. This methodology is a induced result from the previous demostrated studies.

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Measurement of Gamma ray Spectrum for the 27Al(p,3p+n)24Na Nuclear Reaction by using 100 MeV Proton Acceleration System (100 MeV 양성자가속기를 이용한 27Al(p,3p+n)24Na 핵반응에 대한 감마선 스펙트럼 측정)

  • Lee, Samyol
    • Journal of the Korean Society of Radiology
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    • v.9 no.1
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    • pp.55-59
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    • 2015
  • Research about the proton nuclear reaction is actively achieving on the proton therapy including material development of fusion reactor. The proton induced gamma ray energy(2754, 1386 keV) spectrum of 27Al(p,3p+n)24Na reaction was measured with 100 MeV high energy proton beam. The proton beam in the experiment was derived from 100 MeV proton linear accelerator in the KOMAC. We measured the gamma ray intensity ratio of the decay level from the energy spectrum. The previous results have been compared with the current result. Strength of measured gamma rays will provide very important information though decide high energy gamma radiation detection efficiency.

Evaluation of the Performance of Water Quality Models for the Simulation of Reservoir Flushing Effect on Downstream Water Quality (저수지 플러싱 방류가 하류 수질에 미치는 영향 모의를 위한 수질모델의 성능 평가)

  • Jung, Yong Rak;Chung, Se Woong;Yoon, Sung Wan;Oh, Dong Geun;Jeong, Hee Young
    • Journal of Korean Society on Water Environment
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    • v.25 no.1
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    • pp.48-57
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    • 2009
  • A two-dimensional (2D), laterally-averaged hydrodynamic and water quality model, CE-QUAL-W2 was applied to evaluate the performance on simulating the effect of flushing from Daecheong Reservoir on the downstream water quality variations during the flushing events held on November, 2003 and March, 2008. The hydraulic and water quality simulation results were compared with field measurement data, as well as a one-dimensional (1D), unsteady model (KORIV1) that revealed limited capability in the previous study due to missing the resuspension process of river bottom sediments. The results showed that although the 2D model made satisfactory performance in reproducing the temporal variations of dissolved matters including phosphate, ammonia and nitrate, it revealed poor performance in simulating the increase of biological oxygen demand and suspended sediment (SS) concentrations during the passage of the flushing flow. The reason of the error was that the resuspension process of the 2D model is only the function of shear stress induced by wind. In reality, however, as shown by significant correlation between bottom shear stress ($\tau$) and observed SS concentration, the resuspension process can be significantly influenced by current velocity in the riverine system, especially during flushing event. The results indicate that the resuspension of river bottom materials should be incorporated into the water quality modeling processes if $\tau$ is greater than a critical shear stress (${\tau}_c$) for better simulation of flushing effect.

Sequential magnetic resonance spectroscopic changes in a patient with nonketotic hyperglycinemia

  • Shin, Ji-Hun;Ahn, So-Yoon;Shin, Jeong-Hee;Sung, Se-In;Jung, Ji-Mi;Kim, Jin-Kyu;Kim, Eun-Sun;Park, Hyung-Doo;Kim, Ji-Hye;Chang, Yun-Sil;Park, Won-Soon
    • Clinical and Experimental Pediatrics
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    • v.55 no.8
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    • pp.301-305
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    • 2012
  • Nonketotic hyperglycinemia (NKH) is a rare inborn error of amino acid metabolism. A defect in the glycine cleavage enzyme system results in highly elevated concentrations of glycine in the plasma, urine, cerebrospinal fluid, and brain, resulting in glycine-induced encephalopathy and neuropathy. The prevalence of NKH in Korea is very low, and no reports of surviving patients are available, given the scarcity and poor prognosis of this disease. In the current study, we present a patient with NKH diagnosed on the basis of clinical features, biochemical profiles, and genetic analysis. Magnetic resonance spectroscopy (MRS) allowed the measurement of absolute glycine concentrations in different parts of the brain that showed a significantly increased glycine peak, consolidating the diagnosis of NKH. In additional, serial MRS follow-up showed changes in the glycine/creatinine ratios in different parts of the brain. In conclusion, MRS is an effective, noninvasive diagnostic tool for NKH that can be used to distinguish this disease from other glycine metabolism disorders. It may also be useful for monitoring NKH treatment.

The Optimization and Numerical Analysis of The Antenna Circuit for Antenna Design With 13.56MHz As Transmitting Wireless Power (무선전력 전송용 13.56MHz의 안테나 설계를 위한 안테나 회로의 최적화 및 수치적 해석)

  • Chung, Sung-In;Lee, Seung-Min;Lee, Hug-Ho
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.10
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    • pp.57-62
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    • 2009
  • This study proposes the optimization and numerical analysis of the antenna circuit for antenna design with 13.56 MHz as transmitting wireless power, for calculating the dose radiation exposure to the real time. The 13.56 MHz of the antenna frequency bands is used to the loop antenna which is a induced current for transmitting the power with wireless the reader to the tag. The study compared to the real measurement value as calculating the value of the inductance and capacitance through the numerical analysis for the antenna LC resonance using the theory of the electromagnetic induction method. We tried to search for the resonance point as the voltages of both sides of antenna coil by the scope measures of the peak point, as we tried to be variable the resonance capacitor for the optimization tuning of the antenna circuit and the matching of the antenna port. We convince our research contributes to help the design and application technology of the wireless power transmit system which is received power supply with wireless.

A Study on the Image Elements of Sustainable Fashion Design - Focusing on up-cycling bags products - (지속 가능 패션 디자인의 이미지 요소에 관한 연구 - 업사이클링 가방 상품 중심으로 -)

  • Liu Xin;Jae Yoon Chung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.25 no.2
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    • pp.1-16
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    • 2023
  • Due to the current seriousness of environmental pollution and the eco-friendly movement of the fashion industry, research on sustainable fashion design is being actively conducted. In this study, consumer perception of upcycling products, are divided into image, function, and meaning; and image is further divided into shape, color, and material. It was redefined as pattern, and image recognition was evaluated among men and women in their 20s and 30s, and men and women in their 40s and 50s used as subjects. First, factors that determine each image were extracted based on qualitative analysis of the precedent cases of upcycling bags, and quantitative analysis of the subjects was induced through a questionnaire. As a result of the analysis of evaluation items related to image association, the average frequency analysis of all subjects for each stimuli and the cognitive variance of the frequency analysis by generation by gender were found to be similar. However, awareness of some stimuli by generation showed a significant difference. Overall, in the three stimuli with high overall preference, common features, such as the basic box-shaped symmetrical structure, the monochromatic color of the Munsell system, solid and practical texture, and appropriate use of patterns were identified. In addition, it was confirmed that there was a difference with factors such as femininity, simplicity, touch, and splendor in the measurement factors. In conclusion, it is considered that the main significance of this study is that it excluded the recognition and meaning of upcycling products and explored the original design and image elements of products. Therefore, it is expected that this study will be used as a basic data for responding to the gender image of each generation as an alternative method of sustainable fashion design, and it will be an opportunity to expand the scope of the study to a detailed study beyond the biased topic.

A Study on the Development of West Coast Ports by Change of Shipping Environment with Focus on Mokpo Port (해운환경변화에 따른 서해안 항만 발전방안 연구 - 목포항을 중심으로 -)

  • Jin, Hyeong-In;Jeong, Hwan-Ho;Kim, Byeong-Cheol
    • Journal of Korea Port Economic Association
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    • v.24 no.4
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    • pp.71-96
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    • 2008
  • The purpose of this study is to suggest the new strategies for West coast ports, especially Mokpo Port development. This paper also analyzes the recently evolving change of shipping environment such as upsizing of vessels, horizontal and vertical integration strategies in the liner shipping industries through the mergers and acquisitions or strategic alliances, establishment of dedicated terminal and surging bunker charge. With shipping environment is rapidly changing, we examine how to cope with the current situation and suggest the solutions how to tackle shippers' and shipping companies' request. As a result of an empirical study, we found out that Mokpo Port suffers from the shortage of container cargo, container imbalance, insufficient forwarders and inland trucking service providers and hinterland transportation network system. With these obstacles settled, the number of container cargo can be induced to Mokpo Port and the regular container services between Mokpo and Chinese ports and Japanese ports loops were found to be competitive.

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Characterization of the a-Se Film for Phosphor based X-ray light Modulator (형광체 기반 X선 광 변조기를 위한 비정질 셀레늄 필름 특성)

  • Kang, Sang-Sik;Park, Ji-Koon;Cho, Sung-Ho;Cha, Byung-Youl;Shin, Jung-Wook;Lee, Kun-Hwan;Mun, Chi-Woong;Nam, Sang-Hee
    • Journal of Biomedical Engineering Research
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    • v.28 no.2
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    • pp.306-309
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    • 2007
  • PXLM(Phosphor based x-ray light modulator) has a combined structure by phosphor, photoconductor, and liquid crystal and it can realize x-ray image of high resolution in clinical diagnosis area. In this study, we fabricated a photoconductor and investigated electrical and optical properties to confirm application possibility of radiator detector of PXLM structure. As photoconductor, amorphous selenium(a-Se), which is used most in DR(Digital radiography) of direct conversion method, was used and for formation of thin film, it was formed as $20{\mu}m-thick$ by using thermal vacuum evaporation system. For a produced a-Se film, through XRD(X-ray diffraction) and SEM(Scanning electron microscope), we investigated that amorphous structure was uniformly established and through optical measurement, for visible light of 40 $0\sim630nm$, it had absorption efficiency of 95 % and more. After fabricated a-Se film on the top of ITP substrate, hybrid structure was manufactured through forming $Gd_2O_3:Eu$ phosphor of $270{\mu}m-thick$ on the bottom of the substrate. As the result to confirm electrical property of the manufactured hybrid structure, in the case of appling $10V/{\mu}m$, leakage current of $2.5nA/cm^2$ and x-ray sensitivity of $7.31nC/cm^2/mR$ were investigated. Finally, we manufactured PXLM structure combined with hybrid structure and liquid crystal cell of TN(Twisted nematic) mode and then, investigated T-V(Transmission vs. voltage) curve of external light source for induced x-ray energy. PXLM structure showed a similar optical response with T-V curve that common TN mode liquid crystal cell showed according to electric field increase and in appling $50\sim100V$, it showed linear transmission efficiency of $12\sim18%$. This result suggested an application possibility of PXLM structure as radiation detector.

3D Modeling of Turbid Density Flow Induced into Daecheong Reservoir with ELCOM-CAEDYM (ELCOM-CAEDYM을 이용한 대청댐 유입탁수의 3차원 모델링)

  • Chung, Se-Woong;Lee, Heung-Soo;Ryoo, Jae-Il;Ryu, In-Gu;Oh, Dong-Geun
    • Journal of Korea Water Resources Association
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    • v.41 no.12
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    • pp.1187-1198
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    • 2008
  • Many reservoirs in Korea and their downstream environments are under increased pressure for water utilization and ecosystem management from longer discharge of turbid flood runoff compared to a natural river system. Turbidity($C_T$) is an indirect measurement of water 'cloudiness' and has been widely used as an important indicator of water quality and environmental "health". However, $C_T$ modeling studies have been rare due to lack of experimental data that are necessary for model validation. The objective of this study is to validate a coupled three-dimensional(3D) hydrodynamic and particle dynamics model (ELCOM-CAEDYM) for the simulation of turbid density flows in stratified Daecheong Reservoir using extensive field data. Three different groups of suspended solids (SS) classified by the particle size were used as model state variables, and their site-specific SS-$C_T$ relationships were used for the conversion between field measurements ($C_T$) and state variables (SS). The simulation results were validated by comparing vertical profiles of temperature and turbidity measured at monitoring stations of Haenam(R3) and Dam(R4) in 2004. The model showed good performance in reproducing the reservoir thermal structure and propagation of stream density flow, and the magnitude and distribution of turbidity in the reservoir were consistent with the field data. The 3D model and turbidity modeling framework suggested in this study can be used as a supportive tool for the best management of turbidity flow in other reservoirs that have similar turbidity problems.

Current Statues of Phenomics and its Application for Crop Improvement: Imaging Systems for High-throughput Screening (작물육종 효율 극대화를 위한 피노믹스(phenomics) 연구동향: 화상기술을 이용한 식물 표현형 분석을 중심으로)

  • Lee, Seong-Kon;Kwon, Tack-Ryoun;Suh, Eun-Jung;Bae, Shin-Chul
    • Korean Journal of Breeding Science
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    • v.43 no.4
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    • pp.233-240
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    • 2011
  • Food security has been a main global issue due to climate changes and growing world population expected to 9 billion by 2050. While biodiversity is becoming more highlight, breeders are confronting shortage of various genetic materials needed for new variety to tackle food shortage challenge. Though biotechnology is still under debate on potential risk to human and environment, it is considered as one of alternative tools to address food supply issue for its potential to create a number of variations in genetic resource. The new technology, phenomics, is developing to improve efficiency of crop improvement. Phenomics is concerned with the measurement of phenomes which are the physical, morphological, physiological and/or biochemical traits of organisms as they change in response to genetic mutation and environmental influences. It can be served to provide better understanding of phenotypes at whole plant. For last decades, high-throughput screening (HTS) systems have been developed to measure phenomes, rapidly and quantitatively. Imaging technology such as thermal and chlorophyll fluorescence imaging systems is an area of HTS which has been used in agriculture. In this article, we review the current statues of high-throughput screening system in phenomics and its application for crop improvement.