• Title/Summary/Keyword: grounding current

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Users' Status Quo Bias in the Mobile Application Context : From the Myopic Loss Aversion Perspective (근시안적 손실회피 관점에서 본 모바일 애플리케이션 사용자의 현상유지 편향에 관한 연구)

  • Park, Sang-Cheol
    • The Journal of Information Systems
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    • v.24 no.2
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    • pp.189-208
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    • 2015
  • Purpose While individuals have unique abilities for planned behavior, they also often act irrationally. In this study, we draw on myopic loss aversion perspective as a meta-theoretical lens to explain why mobile applications users have inertia from updating their applications, ultimately leading them to use current version of applications. Design/methodology/approach Based on a survey of 219 users, this study conducts its research model using partial least square analysis and also demonstrates that both subconscious triggers (habit and anxiety) of system 1 thinking and conscious triggers (sunk cost and transition cost) of system 2 thinking promotes user's inertia, thus leading to the willness to continue use current versions. Findings By grounding the research model in the combination of both status quo bias and dual information processing theory from the behavioral economics, this study provide an alternative theoretical lens to describe why mobile users hesitate to update their applications. The results of this research show that all triggers have significant impacts on inertia. This study also found that the relationship between inertia and willingness to continue to use current version was positively significant.

Analysis of Soil Ionization Behaviors under Impulse Currents

  • Lee, Bok-Hee;Park, Geon-Hun;Kim, Hoe-Gu;Lee, Kyu-Sun
    • Journal of Electrical Engineering and Technology
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    • v.4 no.1
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    • pp.98-105
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    • 2009
  • This paper presents the characteristics of soil ionization for different water contents, and the parameters associated with the dynamic properties of a simple model grounding system subject to lightning impulse currents. The laboratory experiments for this study were carried out based on factors affecting the soil resistivities. The soil resistivities are adjusted with water contents in the range from 2 to 8% by weight. A test cell with a spherical electrode buried in the middle of the hemispherical container was used. As a result, the electric field intensity $E_c$ initiating ionization is decreased with the reduction of soil resistivities. Also, as the water content increased, the pre-ionization resistance $R_1$ and the post-ionization resistance $R_2$ became lower with increasing current amplitude. The time-lag to ionization $t_1$ and the time-lag to the second current peak $t_2$ at high applied voltages were significantly shorter than those of low applied voltages. It was found that the soil ionization behaviors are highly dependent on the water content and the applied voltage amplitude.

Characteristics and Measurement Method of the Underwater Electromagnetic Signature Emitted from a Naval Ship (함정 발생 수중 전자기장 신호의 특성 및 측정 기법)

  • Yang, Chang-Seob;Chung, Hyun-Ju;Shin, Seung-Je
    • Journal of the Korea Institute of Military Science and Technology
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    • v.9 no.2 s.25
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    • pp.11-19
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    • 2006
  • The underwater electromagnetic signatures of a naval ship are mainly generated from three sources which are the permanent and induced magnetic field in the ship's hull and other ferrous components, the cathodic current electromagnetic field established by the Impressed Current Cathodic Protection(ICCP) system or the Sacrificial Anode and the stray electromagnetic fields generated by onboard equipment. These signatures can be minimized by certain design methods or installation of signature reduction equipment. In this paper, we represented the characteristic of the underwater electromagnetic signature and the signature reduction techniques for a naval ship. Also, we measured the electromagnetic field changes emitted from the real ship using the Electric and Magnetic field Measurement System(EMMS). We found that the underwater electromagnetic signature for a naval ship can be used as input or trigger signal in a surveillance system and an influence mine.

Characteristics for Ground Impedance according to Distance of Current Probe and Frequency (전류보조전극 거리 및 주파수에 따른 접지임피던스 특성)

  • Gil, Hyoung-Jun;Lee, Ki-Yeon;Moon, Hyun-Wook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.5
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    • pp.122-128
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    • 2010
  • This paper presents the characteristics for ground impedance of combined three rods according to distance of current probe and frequency using the fall-of-potential method and the testing techniques to minimize the measuring errors are proposed. The fall-of-potential method is theoretically based on the potential and current measuring principle and the measuring error is primarily caused by the position of auxiliary probes. In order to analyze the effects of ground impedance due to the distance of the current probe and frequency, ground impedances were measured in case that the distance of current probe was located from 5[m] to 20[m] and the measuring frequency was ranged in 55~513[Hz]. The results could be help to determine the position of current probe and the measuring frequency when the ground impedance was measured at grounding system.

Food Sharing Characteristics in Modern Korean Society (현대 한국 식문화에 나타난 함께 나눔의 성격)

  • Oh, Se-Young
    • Journal of the Korean Society of Food Culture
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    • v.20 no.6
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    • pp.683-687
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    • 2005
  • This study examined food sharing characteristics revealed in the modern Korean society by both interpreting phenomena and analyzing literature. Diet was said to be the least influenced by western modernization in Korea. Concerning this matter, one of the important explanations to be considered would be a strong influence of 'the first settlement effect' in culture, as reviewed elsewhere. Sharing food means not only sharing food itself but also sharing communal solidarity. The latter was strongly emphasized in Korean food culture due to his own historical grounding. Some examples revealed in current Korea included sometimes too much generous treat when eating out, even saliva allowed food sharing, too much food provision, and too many restaurants. 'Dutch treat' observed in many occasions of food sharing in Korea was also viewed as a product of historical experience, which was related to the degree of traits of feudalism in modern societies as feudalism was based on a sort of a give and take contract. The association of the degree of traits of feudalism and communal solidarity was explored by comparing so called different meal treat manners between Koreans and Japanese, that is, more generous attitude among the former. The concept of communal solidarity was also examined with respect to Koreans' side dish sharing behaviors which sometimes accompanied seemingly insanitary saliva sharing. In addition, provision of too much food was analyzed by relating this manner to a traditional 'hand over dining table' custom. Traditionally, food on a dining table was not supposed to be only for those sitting on the table. Even though the 'hand over dining table' was no longer well preserved at present time, its cultural traits appeared to be well prevailed in the modern Korean society. Finally, an increase of restaurants as well as an increase of eating out occasions were postulated with respect to the notion that restaurants were the places for ascertaining communal solidarity while sharing foods. The above analyses suggest the importance of the influence of sharing originated from his/her own historical grounding for better understanding of modern Korean food culture.

Analysis of Body Induced Current in Middle Frequency Range Using Quasi-Static FDTD (중간주파수 대역에서 준정적(Quasi-Static) FDTD 기법을 이용한 인체 유도전류 분석)

  • Byun, Jin-Kyu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.1
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    • pp.141-149
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    • 2009
  • In this paper, quasi-static FDTD method is implemented by FORTRAN programming, and it is used for analysis of body induced current in middle frequencies. The quasi-static FDTD program is validated by comparing the calculation result with analytic solution of the test model, to which it is difficult to apply conventional FDTD. It is confirmed that the time-step is reduced by $5.68{\times}10^6$ times. Using validated numerical technique, body induced current distribution in high resolution 3-D human model is calculated for 20[kHz] magnetic field exposure and 1[MHz] electric field exposure. Also, the effect of grounding condition of both feet on the distribution and amplitude of the induced current is analyzed. It is expected that this research can be applied to various fields including safety assessment of body induced current and development of diagnosis devices using bio-electricity.

Stability Evaluation of Series and Parallel Varistor Combination Using Thermal Image Analysis (열화상 분석을 통한 바리스터의 직렬과 병렬 조합의 안전성 평가)

  • Eom, Ju-Hong;Cho, Sung-Chul;Lee, Tae-Hyung;Han, Hoo-Sek
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.8
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    • pp.22-29
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    • 2006
  • According to the recent revision of KS on the basis of the IEC, equipotential grounding systems has been come into focus and the use of surge protective devices(SPD) has been increased radically in order to operate the power system stably. $Z_nO$ varistor with non-linear resistance, which has an outstanding voltage-current(V-I) characteristic, is mainly used in power system to limit surge voltage and divert surge current. $Z_nO$ varistors are packaged several types based on the circuit assembly to be connected to a.c. power line. When the user assemble the $Z_nO$ varistors into parallel or series circuit package, there are my things to be taken into consideration including functions and thermal stability because they are directly related to the safety. We compare stabilities of each assembly type by measuring residual voltage, discharge current, leakage current and surface temperature concerned to the protection performances between a single device with a 40[kA] of current capacity and parallel or series circuits type of varistor package.

A Study on Smart Soil Resistance Measuring Device for Safety Characterized Ground Design in Converged Information Technology (ICT 융합 환경에서의 안전 특성화 접지 설계를 위한 스마트 대지 저항 측정 기술에 관한 연구)

  • Kim, Hong-Yong;Shin, Seung-Jung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.1
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    • pp.203-209
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    • 2019
  • In this work, a new land-specific resistance measuring device (GM) and a measuring probe (Grounding Rod) are connected to the WENNER quadrant as power-line communication (PLC). In groups of two (P1,P2) probes, five to ten probes are installed in series on the ground at intervals of 1m, 2m, 4m, 8m, and 16m, respectively. If the PLC signal from the GMD is detected by the receiver of the Probe 1 (P1) for measurement, the minute voltage and current for measurement flow from the PSD (power supply) attached to the probe to the ground, and then, through the soil between P1 and P2, enters the Probe 1 (P2). The resistance value is then measured by the principle of voltage drop due to ground resistance. Measure the earth resistance every T seconds up to 1 trillion and store the measured data on the Arduino Server mounted on the main equipment. Stored measurement data can be derived from formulas by Ohm's Law and from inherent resistance (here,). Data obtained in real time will be linked to CDGES programs installed on Main PC, enabling data analysis and real-time monitoring of the ground environment on land. In addition, a three-dimensional display is possible with 3D graph support by identifying seasonal characteristics such as temperature and humidity of land (soils). The limitations of the study will require specific application measures of Test Bed for commercial access to a model that has been developed and operated experimentally.

Frequency Dependance of Ground Impedances of the Counterpoises (매설지선 접지임피던스의 주파수 의존성)

  • Choi, Young-Chul;Choi, Jong-Hyuk;Kim, Dong-Kyu;Lee, Gyu-Sun;Yang, Soon-Man;Lee, Su-Bong;Lee, Bok-Hee;Ahn, Chang-Hwan
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1489_1490
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    • 2009
  • Ground impedance is changed according to frequency of the current injected into the grounding system. Because the lightning surge gives a broad frequency spectrum from some ten Hz to a few MHz, frequency dependance of ground impedance must be evaluated. In this paper, we have constructed 10m, 30m, 50m counterpoise and evaluated frequency dependance of ground impedance. Also we have evaluated frequency dependance of ground impedance according to current injection point. As a result, long counterpoises have low ground resistance, but ground impedances of those are significantly increased in the range of high frequency. In the case that currents are injected into the center of counterpoise, the ground impedance is most lower than any other injection point. Also, additory ground rod of 1.8m long affect ground impedance decrease.

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Approaches to Suppressing Shaft Voltage in Non-Insulated Rotor Brushless DC Motor driven by PWM Inverter

  • Isomura, Yoshinori;Yamamoto, Kichiro;Morimoto, Shigeo;Maetani, Tatsuo;Watanabe, Akihiko;Nakano, Keisaku
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.3
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    • pp.241-247
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    • 2014
  • The voltage source PWM inverter generally used to drive the air conditioning (A/C) fans has been posing a large issue that the bearings in air conditioning fan motors are highly possible to be corroded electrically. Potential difference called shaft voltage is generated between inner and outer rings of the bearings due to inverter switching. The shaft voltage causes bearing lubricant breakdown dielectrically. As a result, bearing current is caused. This current causes the bearing corrosion. In previous work, we demonstrated that the shaft voltage can be reduced by using an insulator inserted between the outer and inner cores of the rotor in an air conditioning fan motor without grounding. This paper proposes the other countermeasure for reducing the shaft voltage in fan motors. The countermeasure which adds a capacitor between the brackets and the stator core is effective even for fan motors with non-insulated rotor. The effectiveness is confirmed by both simulated and experimental results.