• Title/Summary/Keyword: Mean current

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The effect of pulse parameters on the composition and the structure of Palladium-Nickel alloy electrodeposits (팔라디움-니켈 합금전착층의 조성 및 조직에 미치는 파형전류인자의 영향)

  • 예길촌;오유청
    • Journal of the Korean institute of surface engineering
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    • v.27 no.5
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    • pp.285-291
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    • 1994
  • The effects of pulse current parameters on the composition and the microstructure of Pd-Ni alloy electrodeposits were studied. The cathode current efficiency of p.c. electrolysis conditions decreased with increasing both mean and peak current density and was lower than those under D.C. electrolysis condition. Palladium content of Pd-Ni alloy increased with increasing both peak current density and on-time, while it decreased with increasing mean current density and duty cycle. The preferred orientation of Pd-Ni alloys changed with increasing mean current density in the sequence of (111)+(110).(100) or (110)longrightarrow(111)longrightarrow(100) or random distribution of crystal structure. The surface morphology of Pd-Ni alloy changed mainly according to the mean current density and was related to the preferred orientation.

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An Estimation Of Average Current Velocity In The Western Channel Of The Korea Strait From Mean Sea Level Data

  • Lee, Jae Chul;Jung, Chang Hee
    • 한국해양학회지
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    • v.12 no.2
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    • pp.67-74
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    • 1977
  • With the serial observation data and the tidal records at Busan and Izuhara from 1966 to 1973, the geostrophic current velocity and its relation to the difference of mean sea level of both sides were studied in order to estimate indirectly the average current velocity from the tidal observations. The results shows that the current velocity is estimated by the relationship V=4.016(H-98.3) with the 95% confidence limits of V 4.2 cm/sec. Ther relationship between the observed current velocity and the simultaneous daily mean sea level difference shows a similar result, V=4.717(H-99.6). The two equations were applied to the evaluation of annual variations of current velocity from the average monthly mean sea level data of both stations.

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The effect of pulse current electrolysis on the composition and themicrostructure of Tin-Zinc electrodeposits (주석-아연 합금도금층의 조성 및 조직에 미치는 파형전류전해의 영향)

  • 예길촌;박성진;김대영
    • Journal of the Korean institute of surface engineering
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    • v.34 no.4
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    • pp.303-312
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    • 2001
  • Composition and microstructure of the tin-zinc alloys electroplated in gluconate bath were studied according to pulse current parameters. The cathode current efficiency increased with both the mean current density and the off-time decrease. Zinc content of the alloy deposits increased with increasing mean current density, while it decreased noticebly with increasing the off-time from 10-30ms to 100-150ms. The preferred orientation of the alloy deposits changed with the increase of peak current density in the sequence of (220)longrightarrow(220)+(420) or (220)+(420)+(321) mixed structure. The equiaxed grain size of the alloy increased with the increase of off-time and the decrease of mean current density.

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Experimental investigation of electric currents flowing through human body in electirc shock (전기충격시인체에 흐르는 전류의 실험적 고찰)

  • 김완배;안광윤;윤태원
    • 전기의세계
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    • v.29 no.1
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    • pp.21-27
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    • 1980
  • The effect of electric shock on human body is enormousness, which leads to warmth, tingling, and even death. The mean values of perception currents obtained on 91 men and 39 women are about 0.77(mA) for men and 0.57(mA) for women. The mean value for women is approximately seven tenths that of men. An individual can tolerate, with no adverse effects, repeated exposure to the reactions associated with currents of his let-go level, and the mean value of let-go currents obtained from 27 normal men is 6.29(mA). Lethal currents flowing human body is very dangerous even for a short time. So, it is necessary to have recourse to animal experiments ot determine lethal current for human. An analysis of experimental data indicates that body weight and shock duration are important factors in determining the lethal current. It is suggested that the relationship between current and shock duration is given by I=K/.root.T, and lethal current is proportional to body weight, where I is the current in milliampere, and T is the time in seconds.

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Analysis of Characteristics of All Solid-State Batteries Using Linear Regression Models

  • Kyo-Chan Lee;Sang-Hyun Lee
    • International journal of advanced smart convergence
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    • v.13 no.1
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    • pp.206-211
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    • 2024
  • This study used a total of 205,565 datasets of 'voltage', 'current', '℃', and 'time(s)' to systematically analyze the properties and performance of solid electrolytes. As a method for characterizing solid electrolytes, a linear regression model, one of the machine learning models, is used to visualize the relationship between 'voltage' and 'current' and calculate the regression coefficient, mean squared error (MSE), and coefficient of determination (R^2). The regression coefficient between 'Voltage' and 'Current' in the results of the linear regression model is about 1.89, indicating that 'Voltage' has a positive effect on 'Current', and it is expected that the current will increase by about 1.89 times as the voltage increases. MSE found that the mean squared error between the model's predicted and actual values was about 0.3, with smaller values closer to the model's predictions to the actual values. The coefficient of determination (R^2) is about 0.25, which can be interpreted as explaining 25% of the data.

Differences in Depression, Anxiety, Self-esteem According to the Degree of Obesity in Women -A Pilot Study- (여성에 있어서의 비만도에 따른 우울, 불안, 자아존중감의 차이 -기초연구-)

  • Lee, Jun-Hwan;Kim, Gwang-Ho;Kim, Jong-Woo
    • Journal of Oriental Neuropsychiatry
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    • v.13 no.2
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    • pp.93-100
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    • 2002
  • Objects and Methods : BDl, STAI and Self-Esteem scale were completed by 28 female subjects who composed of nurses of Kyung Hee Medical Center and students of Kyung Hee Oriental Medical college. At the same time, current weight, height and BMI(Body Mass Index), ideal weight, height and BMI, the difference of current weight and ideal weight, the difference of current height and ideal height, and the difference of current BMI and ideal BMI were measured. Result : 1. There was a significant difference between obese and normal weight group in the difference between the current weight and the ideal weight. The difference of the obese group were higher than the normal weight group. 2. There was a significant difference between obese and normal weight group in the mean BDI score. The mean BDI score of the obese group were higher than that of the normal weight group. 3. There was no significant difference between obese and normal weight group in the mean STAI score. 4. There was no significant difference between obese and normal weight group in the mean Self-Esteem Scale score. Conclusion : There are a tendency; the more weight, the more depression in women.

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Efficient Rotor Fault Detection of Induction Motors Using Stator Current Spectrum Monitoring (고정자 전류 스펙트럼 모니터링을 이용한 효과적인 유도전동기 회전자 고장 걸출)

  • 정춘호;우혁재;송명현;강의성;김경민
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.6
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    • pp.873-878
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    • 2002
  • Stator current spectrum by the fast Fourier transform (FFT) of current signals has been widely used for fault detection in induction motors. In this paper, we propose efficient rotor fault detection of Induction motors using stator current spectrum monitoring. The proposed method utilizes the mean absolute difference (MAD) between a Predetermined reference vector and a feature vector extracted from the stator current spectrum. Our proposed approach requires a smaller amount of computations when compared to fault detection algorithms based on neural networks, since it uses simple MAD criterion to detect rotor faults related broken rotor bars. Experimental results show that our proposed method can successively detect the rotor fault of the induction motor.

Characteristics of tidal current and mean flow at the west channel of Yeoja Bay in the South Sea of Korea (여자만 서수도 해역의 조류 및 조석평균류 특성)

  • CHOO, Hyo-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.3
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    • pp.252-263
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    • 2019
  • In order to understand the tidal current and mean flow at the west channel of Yeoja Bay in the South Sea of Korea, numerical model experiments and vorticity analysis were carried out. The currents flow north at flood and south at ebb respectively and have the reversing form in the west channel. Topographical eddies are found in the surroundings of Dunbyong Island in the east of the channel. The flood currents flow from the waters near Naro Islands through the west channel and the coastal waters near Geumo Islands through the east channel. The ebb currents from the Yeoja Bay flow out along the west and the east channels separately. The south of Nang Island have weak flows because the island is located in the rear of main tidal stream. Currents are converged at ebb and diverged at flood in the northwest of Jeokgum Island. Tidal current ellipses show reversing form in the west channel but a kind of rotational form in the east channel. As the results of tide induced mean flows, cyclonic and anticyclonic topographical eddies at the northern tip but eddies with opposite spin at the southern tip are found in the west channel of Yeoja Bay. The topographical eddies around the islands and narrow channels are created from the vorticity formed at the land shore by the friction between tidal currents and the west channel.

Variability of the Coastal Current off Uljin in Summer 2006 (2006년 하계 울진 연안 해류의 변동성)

  • Lee, Jae Chul;Chang, Kyung-Il
    • Ocean and Polar Research
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    • v.36 no.2
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    • pp.165-177
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    • 2014
  • In an effort to investigate the structure and variability of the coastal current in the East Sea, a moored ADCP observation was conducted off Uljin from late May to mid-October 2006. Owing to the transition of season from summer to autumn, the features of the current and wind can be divided into two parts. Until mid-August (Part-I), a southward flow is dominant at all depths with a mean alongshore velocity of 4.2~8.9 cm/s but northward winds are not strong enough to reverse the near-surface current. During Part-II, a strong northward current occurs frequently in the upper layer but winds are predominantly southward including two typhoons that have deep-reaching influence. Profile of mean velocity has three layers with a northward velocity embedded at 12~28 m depth. The near-surface current of Part-II significantly coheres with winds at 4-8 day periods with a phase lag of about 12 hours. The modal structure of the current obtained by EOF analysis is: (1) Mode-1, having 83.6% of total variance, represents the current in the same direction at all depths corresponding to the southward North Korean Cold Current (NKCC). (2) Mode-2 (11.7%) reveals a two-layer structure that can be explained by the northward East Korean Warm Current (EKWC) in the upper layer and NKCC in the lower. (3) Mode-3 (2.6%) has three layers, in which the EKWC is reversed near the surface by opposing winds. This mode is particularly similar to the mean velocity profile of Part-II.

Tidal Currents In The Channel Near Incheon Harbour (인천항부근 수로의 조류)

  • Bong, Jong Hon
    • 한국해양학회지
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    • v.13 no.1
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    • pp.29-34
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    • 1978
  • Simultaneous tidal current observation at five or seven stations on the channel near Incheon Habour was conducted at neap, mean and spring tides during the period of August 16 to August 27, 1976 and the characteristic of tidal currents with each tide was studied by the analysis of these data. Times of slack refer to the times of high and low waters at neap, mean and spring tides seem to be small. Times of maximum current refer to the times of high and low waters at the mean tide tends to appear earlier than that of the neap tide and later than that of the spring tide. The velocity ratio of maximum ebb current to maximum flood current at the mean tide has larger value than that of neap tide and has smaller value than that of spring tide. The current velocity ratio of spring tide to neap tide and to mean tide are approximately 1.8 and 1.3, respectively.

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