• Title/Summary/Keyword: Gradients

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A Review on Nuclear Magnetic Resonance Logging: Simulation Schemes (자기공명반응 시뮬레이션 해설 및 비교)

  • Jang, Jae Hwa;Nam, Myung Jin
    • Geophysics and Geophysical Exploration
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    • v.16 no.2
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    • pp.97-105
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    • 2013
  • Nuclear magnetic resonance (NMR) logging has become an important technique for formation evaluation, detecting interaction signals between H protons and applied magnetic fields. Measured decay signals called relaxation, contain important information about density of H protons and different decay rate due to its fluid type in the sensitive area. Thus, petrophysical information such as porosity, permeability and wettability can be estimated through the interpretation of the decay signals. Many researches on random walk simulation have been published, since a simulation method based on random walk for solving exponential decays was adapted in the early of 1950. This study first makes a review on NMR simulation researches, explains two most important methods: simulation with or without considering magnetic field gradient. Lastly, the study makes a comparison between NMR simulation responses with and without magnetic field gradient to show the importance to consider magnetic gradient to analyze the effects of magnetic gradients on NMR responses.

The Study on the Effect of Passenger Coach temperature When Aircurtains Installed At Electrical Rolling Stock At Entrance Door (전동차 출입문에 에어커튼 설치시 객실 온도 변화 연구)

  • Ahn Jong-Kon;Kim Chul-Ho;Park Duk-Sin
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.489-496
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    • 2004
  • The effect of airconditioning and heating system when aircurtains installed in subway electrical rolling stock at entrance door. It blocks cold/hot air of outside. It is good for health with its blocking effect against dusts exhaust fumes, odor bugs and smoke from outside. It always maintains clean and pleasant atmosphere inside. It helps you to have health with its ever-equal temperature distribution at inside. It saves lots of maintenance cost for heating/cooling (about 86$\%$) since it cuts the loss of hot air under heating as well as of cold air under air-conditionin. Customers can feel pleasant go in and out (better than before) with the door. It is an indispensable product for the employers to cut the cost. It makes customers feel pleasant near doors, since it isnt influenced by temperature difference of cold/hot air when the door opens/closes. In electrical rolling stock passenger temperature is a lot different from that the door opens/closes. One of the main aims is to create an acceptable thermal environment without draught problem. Temperature, gradients when aircurtains installed in subway electrical rolling stock at entrance door have been studied. And the temperature measured at 0.1, 0.5, 1.3, 1.7m above the floor. It has been found that temperature, with large fluctuations caused more draught influence.

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Moving Object Classification through Fusion of Shape and Motion Information (형상 정보와 모션 정보 융합을 통한 움직이는 물체 인식)

  • Kim Jung-Ho;Ko Han-Seok
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.43 no.5 s.311
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    • pp.38-47
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    • 2006
  • Conventional classification method uses a single classifier based on shape or motion feature. However this method exhibits a weakness if naively used since the classification performance is highly sensitive to the accuracy of moving region to be detected. The detection accuracy, in turn, depends on the condition of the image background. In this paper, we propose to resolve the drawback and thus strengthen the classification reliability by employing a Bayesian decision fusion and by optimally combining the decisions of three classifiers. The first classifier is based on shape information obtained from Fourier descriptors while the second is based on the shape information obtained from image gradients. The third classifier uses motion information. Our experimental results on the classification Performance of human and vehicle with a static camera in various directions confirm a significant improvement and indicate the superiority of the proposed decision fusion method compared to the conventional Majority Voting and Weight Average Score approaches.

Experimental Study on the Characteristics of Combustion in Indirect Moxibustion with Cake Insulation (격병구(隔餠灸)(부자구(附子灸),호초구(胡椒灸))의 연소특성(燃燒特性)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Lee, Geon-hui;Lee, Geon-mok;Guk, Uo-suk
    • Journal of Acupuncture Research
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    • v.21 no.6
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    • pp.233-248
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    • 2004
  • Objective : The purpose of this study is to investigate the mechanism and effect of moxibustion with monkshood cake, slice & black pepper cake. objectively, to be used as the quantitative data through the measurement of temperatqre, and to grasp the thermodynamic characteristics of moxibustion with monkshood cake, slice & black pepper cake. Methods : We have selected of the moxibustion with monkshood cake, slice & black pepper cake. indirect moxibustion. We make a comparative study of the thermodynamic characteristics of moxibustion with monkshood cake, slice & black pepper cake. We examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa. Results & Conclusions : 1. We can design the moxibustion with monkshood cake that it has thermodynamic characteristics of 173sec effective combustion time, $44^{\circ}C$ maximum temperature, $0.22^{\circ}C/sec$ ascending maximum temperature, if we use 3mm thickness or 3mm and below of monkshood cake and the moxa cone is formed the conical shape that the base diameter was 8mm, the height was 10mm, the density was $600mg/cm^3$. 2. We can design the moxibustion with monkshood cake that it has thermodynamic characteristics of 205~271sec effective combustion period time, $44.6{\sim}46.1^{\circ}C$ maximum temperature, $0.18{\sim}0.24^{\circ}C/sec$ ascending maximum temperature, if we use 3mm thickness of monkshood cake and the moxa cone is formed the conical shape that the base diameter was 8mm, the height was 10mm, the density was $480{\sim}720mg/cm^3$.

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The Clinical Study on 80 Cases of Low Back Pain Patients (요통환자 80례에 대한 임상적 고찰)

  • Jeon, Seong-Ha;Ryu, Heon-Sik;Chang, Byoung-Son;Kim, Su-Hyun;Park, Hoi-Jin
    • Journal of Acupuncture Research
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    • v.24 no.2
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    • pp.155-167
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    • 2007
  • Objectives : This study was performed to evaluate the general distribution and the efficacy of oriental medical treatment for low back pain. Methods: We have selected of the moxa bucket moxibustion. We make a comparative study of the thermodynamic characteristics of moxa bucket moxibustion. We examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa bucket moxibustion made by oak wood. Results : The 80 cases of low back pain patients was analyzed according to the distribution of sex, age, the period of disease, contributing factor, the patient-condition on admission, the symptom on admission, the duration of admission, the reading of the X-ray and the treatment efficacy was evaluated respectively. 1. Female was more than male in the ratio of 1:1.2, and thirties and seventies 25% the most, the acutest phase 46.3% the most, reason unknown 33.8% the most, Grade III 50% the most, L.B.P. only 51.3% the most, the day of 6-10 30% the most, compression Fx 30% the most. 2. In the total treatment result, the good was 51.3%, the excellent 22.5%, the fair 17.5%, the poor 8.8% in order. About 'the effective rate'(the percentage of positive effective treatment cases) of each distribution, the fifties 100% the most, the acutest phase 97.3% the most, the slip down, weight lifting, overuse 100% the most respectively, Grade III 97.5% the most, L.B.P. only 95.1% the most, the day of 11-15 100% the most, HN.P. 93.3% the most. Conclusions : We have known the efficacy of oriental medical treatment for L.B.P. was good and early treatment was better than late treatment and main cause of L.B.P. was degenerative change.

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Real-time Interactive Control of Magnetic Resonance Imaging System Using High-speed Digital Signal Processors (고속 DSP를 이용한 실시간 자기공명영상시스템 제어)

  • 안창범;김휴정;이흥규
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.40 no.5
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    • pp.341-349
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    • 2003
  • A real time interactive controller (spectrometer) for magnetic resonance imaging (MRI) system has been developed using high speed digital signal processors (DSP). The controller generates radio frequency (rf) waveforms and audio frequency gradient waveforms and controls multiple receivers for data acquisition. By employing DSPs having high computational power (e.g., TMS320C670l) real time generation of complicated gradient waveforms and interactive control of selection planes are possible, which are important features in real-time imaging of moving organs, e.g., cardiac imaging. The spectrometer was successfully implemented at a 1.5 Tesla whole body MRI system for clinical application. Performance of the spectrometer is verified by various experiments including high- speed imaging such as fast spin echo (FSE) and echo planar imaging (EPI). These high-speed imaging techniques reduce measurement time, however, usually intensify artifact if there is any systematic phase error or jitter in the synchronization between the transmitter, receiver, and gradients.

A Driver's Condition Warning System using Eye Aspect Ratio (눈 영상비를 이용한 운전자 상태 경고 시스템)

  • Shin, Moon-Chang;Lee, Won-Young
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.2
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    • pp.349-356
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    • 2020
  • This paper introduces the implementation of a driver's condition warning system using eye aspect ratio to prevent a car accident. The proposed driver's condition warning system using eye aspect ratio consists of a camera, that is required to detect eyes, the Raspberrypie that processes information on eyes from the camera, buzzer and vibrator, that are required to warn the driver. In order to detect and recognize driver's eyes, the histogram of oriented gradients and face landmark estimation based on deep-learning are used. Initially the system calculates the eye aspect ratio of the driver from 6 coordinates around the eye and then gets each eye aspect ratio values when the eyes are opened and closed. These two different eye aspect ratio values are used to calculate the threshold value that is necessary to determine the eye state. Because the threshold value is adaptively determined according to the driver's eye aspect ratio, the system can use the optimal threshold value to determine the driver's condition. In addition, the system synthesizes an input image from the gray-scaled and LAB model images to operate in low lighting conditions.

Effects of Environmental Factors on Growth and Nitrogen Fixation Activity of Kummerowia striata (매듭풀의 생육과 질소고정 활성에 미치는 환경요인의 영향)

  • Song, Seung-Dal;Jung-Sook Park;In-Sook Kim
    • The Korean Journal of Ecology
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    • v.18 no.1
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    • pp.43-54
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    • 1995
  • Effects of environmental factors of N, P, pH, moisture, temperature and oxygen on growth and nitrogen fixation activity of kummerowia striate (Thunb.) Schindler seedling, bearing symbiotic root nodules, were quantitatively analyzed during the growing period. The specific nitrogenase activity (ARA) of nodules showed the maximum value of 187 μmol C₂H₄g fr wt-1 h-1 6 weeks after seeds were germinated. The total nitrogenase activities per plant attained as 1.56, 0.85, 0.09 and 4.0, 1.11, 0.04 μmol C₂H₄hr-1, respectively for the treatments of 1, 3 and 5 mM NO₃ ̄and NH₄+ on the 60th day. While the plant grown in N-free media for 20 days after treatments of 5 mM NH₄+for 40 days resulted in 30 mg fr wt of nodule formation and exhibited the relative activities of 152% and 162% for total and specific ARA in comparison with those of control plant grown with N-free for 60 days. Total biomass and ARA was by 70% and 86% lower in N and P deficiency, respectively. The N and P deficient plot showed 70% and 86% decreases of total biomass and ARA in comparison with those of control. The plant grown with N-free for 20 days after pretreatment with N and P free media for 40 days showed the relative values of 77%, 118% and 150%, respectively for nodule biomass, total and specific ARA in comparison with those of control. The treatment with acid or alkali gradients resulted in significant decreases of nodule biomass and ARA. The optimum temperature and pO₂for ARA were 30°C and 40 kPa, respectively. Two peaks of diurnal variation appeared at 11:00 and 23:00 o'clocks by the continuous light condition. The plants with water stress by temporary wilting point rsulted in 95~97% inhibition for nodule respiration, transpiration and specific ARA. Transpiration and ARA ware recovered to 88% and 38% of those of water unstressed plants, respectively, 6 hours after the plants were rewatered from water stressed condition.

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Effects of Sewage Sludge Application on the Growth and KDICical Composition of Altari Radish (Raphanus sativus) (도시 하수 슬러지 투여가 알타리무의 생육과 화학성분에 미치는 영향)

  • Oh, In-Hye;Sang-Uk Lee;Wha Mo Yoon
    • The Korean Journal of Ecology
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    • v.19 no.3
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    • pp.271-282
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    • 1996
  • This study was aimed to observe the effects of municipal sewage sludge as a organic fertilizer on the growth and KDICical omposition of Altari radish (Raphanus sativus). The accumulation rate of heavy metals of the sludge in the radish was also observed. Municipal sewage sludge of Taejon City was applied to the soil of Pai-Chai University Farm to make 6 gradients of sludge contents in the soil. Root weight of Altari radish was affected significantly by N and P contents in the soil. The longest leaves and roots were produced in the control group, in which urea was applied as nitrogen source to the soil. Even though any other sludge-applied groups produced shorter leaves and roots than the control group, the length of the leaves and roots and the weight of the whole plant of the radish tended to increase with the increase of the sludge application. Contents of N, K, Ca and Mg in the radish were not significantly different among those in 6 experimental groups, but P contents in leaves varied among the 6 groups. Zn content of spring Altari radish treated with 200% sludge was 57.6 mg/kg. It is the highest contents among 6 experimental groups. Contents of Zn, Mn and Cd were higher in leaves than in roots, but less than those in market vegetables. From the above results, it is concluded that municipal sewage sludge can be applied as organic fertilizer to the growth of Altari radish. But this sludge could not be applied under our current regulations, which must be reviewed at intra-governmental leavels.

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Chemical and ecological studies of grasslands and soils of the Young-dong in Seoul, Korea (영동지구의 야초지와 토양에 대한 화학적, 생태학적 연구)

  • 박봉규;한진순
    • The Korean Journal of Ecology
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    • v.3 no.1_2
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    • pp.1-10
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    • 1980
  • This study was carried out to find out the correlation between plant groups and environomental gradient in the native grassfild near Kang Nam Express Terminal from August 26 to september 15, 1977. The correlations among plant species were calculated by using the method of x2 and the various relationships among soil environmental gradients were grouped by means of correlation coefficient. As a result, both the species and the soil environmental factors could be subdivided into four groups, and the four groups of the native grassfield were turned out to be correlated with the four groups of soil environmental factors. The first plant group (Panicum dichotomiflorum, Chenopodium album, Bidens forndosa, Humulus japonicus, Alopeculus amurensis, Potentilla fragarioides, Centipeda minima, Beckmannia erucaeformis) was formed in the releve 1∼10 reagions, organic matter by Turins's method, Total N, Exchange Ca and total of Exchange K, Na, Kg, Ca were abundent. The second plant group (Digitaria sanguinalis, Paltulaca oleracea, Echinochlea macrocrovi, Cyperus amuricus) was formed in the relve 11∼18 reagions, where Exchange Ca and total of Exchange K, Ng, Mg, Ca were little but Exchange A1 and sand were aburdent. In relve 19∼20 reagions, with much of Exchange Ca, total of Exchange K, Na, Mg, Ca, pH and a little Exchange Al, was found the third plant group (Pycreus sanguinoloentus, Cyperus amuricus, Ludwigia prostrata, Echinochloa echinata, Polygonum thunbergii, Salix glandulosa seedling) The fourth plant group (Cassia nomame, Polygnoum perfoliatum, Setaria viridis, Glocien ussuriensis, Lactuca indica, setaria glauca, Artemisia capill aris, Artmisia asiatica, Calamagrostis arundinacea, Kummerowia striata, Denothera odorata, Artemisia japonica, Carey laceolata) was formed in relve 21∼25 reagions, where organic matter by loss on ignition, Exchange Mg and Maximum water holding capacity were abundent but sand was a little. Thus it can be concluded that there is a close relationship between the vegetation group clasified by meaus of x2 and the environtal factors of soil devided by means of correlations coefficient.

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