• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.604-606
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• 2011

Purpose This study analyzes resistance spot weldability of DP60 steels. Methodology To compare the resistance spot weldability of DP60 steels, tensile strength test and macro-section test were conducted for the resistance spot welds. Acceptable welding conditions were determined as a function of the resistance spot welding process parameters such as electrode force, welding time, and welding current. The lower limit of the welding lobe was the minimum shear tension strength for 590MPa-grade steel while the upper limit was determined whether or not expulsion was detected. Findings Welding force is 200kgf more appropriate in terms of 300kgf the larger the width of the welding zone. Acceptable welding current condition and welding lobe were changed depending on welding force. Research limitations This study is forced on inverter DC resistance spot weldability of 590Mpa-grade steels for automotive application. Practical implications This study confirms the weldability of DP60 steel by comparing resistance spot weldability depending on welding force. Originality This study analysed resistance spot weldability depending on welding force. wedability of DP60 steel were determined by welding lobes.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.2
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• pp.88-94
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• 2013

The primary objective of the current work is to obviously analyze regarding effects of trim conditions of a ship on resistance performance using model test and CFD. Model tests at a towing tank are conducted to investigate resistance for trim conditions at the given same displacement. Measured resistance shows small but distinct differences according to trim conditions. However, these differences are difficult to be clarified by measured physical quantities and wave pattern analysis from model tests. CFD is employed for the assessment of resistance performance according to trim conditions. The flow computation is conducted considering free surface and dynamic trim using a commercial CFD code (STAR-CCM+). The initiative of the present work is to systematically demonstrate pressure resistance acting on each region of divided finite zones of ship surface along the length and draught direction of surface when pressure distribution on the ship is interpreted. Also, a standard to assess the pressure resistance applied on the divided regions of a ship is established.

• Journal of Power Electronics
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• v.18 no.4
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• pp.1268-1277
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• 2018

A relatively high operating frequency is required for efficient wireless power transfer (WPT). However, the alternating current (AC) resistance of coils increases sharply with operating frequency, which possibly degrades overall efficiency. Hence, the evaluation of coil AC resistance is critical in selecting operating frequency to achieve good efficiency. For a Litz wire coil, AC resistance is attributed to the magnetic field, which leads to the skin effect, the proximity effect, and the corresponding conductive resistance and inductive resistance in the coil. A numerical calculation method based on the Biot-Savart law is proposed to calculate magnetic field strength over strands in Litz wire planar spiral coils to evaluate their AC resistance. An optimized frequency can be found to achieve the maximum efficiency of a WPT system based on the predicted resistance. Sample coils are manufactured to verify the resistance analysis method. A prototype WPT system is set up to conduct the experiments. The experiments show that the proposed method can accurately predict the AC resistance of Litz wire planar spiral coils and the optimized operating frequency for maximum efficiency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.4
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• pp.298-302
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• 2010

We investigated the resistance change behavior of SABiT (Samsung Advanced Bump interconnection Technology) technology-applied PCB (Printed Circuit Board) with the various bump sizes and fabrication conditions. Many testing samples with different bump size, prepreg thickness, number of print on the formation of Ag paste bump, were made. The resistance of Ag paste bump itself was calculated from the Ag paste resistivity and bump size, measured by using 4-point probe method and FE-SEM (Field Emission Scanning Electron Microscope), respectively. The contact resistance between Ag paste bump and conducting Cu line were obtained by subtracting the Cu line and bump resistances from the measured total resistance. It was found that the contact resistance drastically changed with the variation of Ag paste bump size and the contact resistance had the largest influence on total resistance. We found that the bump size and contact resistance obeyed the power law relationship. The resistance of a circuit in PCB can be estimated from this kind of relationship as the bump size and fabrication technique vary.

• Management & Information Systems Review
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• v.23
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• pp.233-260
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• 2007

Now a day, Information and its related system has been more important in our competitive environment. In this situation, there is also an important thing that we must take into consideration, that's the employer's resistance. Until now we have little material concerning the issue, user's resistance. Owing to that, it's a little hard to study the user's resistance against the IS. Dealing with the resistance effectively helps companies save a great deal of cost and build the information system successfully. This paper takes the Markus's theories about user's resistance. According to the theories, there are three keys theories affecting resistance. To sum this, people-oriented theory, system-oriented theory and Interaction theory. To complement the theories, this paper includes another theories related with resistance and takes total seven factors causing user's resistance. Among these seven factors, four factors have a meaningful effect on the user's resistance, that is, Self-efficacy, System Complexity, Threat of the one's status and politics and System Staff's service quality. Managers and system-related company should keep it in mind very carefully, and I hope they make the best use of the result of this study.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.5.1-5.1
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• 2009

Organic photovoltaic (OPV)cells have attracted considerable attention due to their potential for flexible, lightweight, and low-cost application of solar energy conversion. Since a 1% power conversion efficiency (PCE) OPV based on a single donor-acceptor heterojunction was reported by Tang, the PCE has steadily improved around 5%. It is well known that a high parallel (shunt)resistance and a low series resistance are required simultaneously to achieve ideal photovoltaic devices. The device should be free of leakage current through the device to maximize the parallel resistance. The series resistance is attributed to the ohmic loss in the whole device, which includes the bulk resistance and the contact resistance. The bulk resistance originated from the bulk resistance of the organic layer and the electrodes; the contact resistance comes from the interface between the electrodes and the active layer. Furthermore, it has been reported that the bulk resistance of the indium tin oxide (ITO) of the devices dominates the series resistance of OPVs for a large area more than $0.01\;cm^2$. Therefore, in practical application, the large area of ITO may significantly reduce the device performance. In this work, we investigated the effect of sheet resistance ($R_{sh}$) of deposited ITO on the performance of OPVs. It was found that the device performance of polythiophene-fullerene (P3HT:PCBM) bulk heterojunction OPVs was critically dependent on Rsh of the ITO electrode. With decreasing $R_{sh}$ of the ITO from 39 to $8.5\;{\Omega}/{\square}$, the fill factor (FF) of OPVs was dramatically improved from 0.407 to 0.580, resulting in improvement of PCE from $1.63{\pm}0.2$ to $2.5{\pm}0.1%$ underan AM1.5 simulated solar intensity of $100\;mW/cm^2$.

• Journal of the Korean Ceramic Society
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• v.33 no.11
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• pp.1231-1236
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• 1996

The electrode resistance of semiconducting PTC BaTiO3 ceramic material was studied in some detail. Comme-rical In-Ag paste In-Ga alloy and electroless plated Ni as well as evaporated Al were chosen as electrode. The contact resistance of electroded samples were measured by both dc resistivity and ac impedance analysis. The aging effect on contact resistance under cyclic loading from -1$0^{\circ}C$ to 85$^{\circ}C$ was also monitored for the prolonged period of time. In case of Al electroded samples the heat treatment and protective coating had effects on the stability against contact resistance degradation. It was also found that the samples with commercial In-Ag paste and electroless plated Ni electrode had good properties of contact resistance against aging.

• Journal of the Korea Safety Management & Science
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• v.16 no.1
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• pp.191-199
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• 2014

This paper reviewed the relationship among CEO's entrepreneurship/risktaking, innovation resistance and innovation performance, and the mediating effect of innovation resistance between CEO's entrepreneurship/risktaking and innovation performance. Based on the responses from 219 companies, the results of multiple regression analysis appeared as follow; 1) CEO's entrepreneurship and risktaking effect negatively on innovation resistance. 2) innovation resistance negatively on innovation performance(process innovation, organization innovation). 3) innovation resistance mediates partly between CEO's entrepreneurship/risktaking and innovation performance.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.113-118
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• 2008

We have developed an integrated giant magneto resistance using not only circuit but also integrating technique with semiconductor for automobile application. It has four elements used for giant magneto resistance sensor. Ni-Fe/Cu multi layers were prepared on a glass substrate by magnetron sputtering. The dependence of magneto resistance on the thickness of the Ni-Fe and Cu layers was investigated. The MR ratio showed a saturated a peak at Cu layer $10{\AA}$, Ni-Fe layer $50{\AA}$, where the MR ratio is about 8.7% at room temperature. By means of Ni-Fe multi film and specific integrating technique, these new giant magneto resistance sensor showed excellent resistance characteristics.

• Journal of Information Technology Applications and Management
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• v.22 no.4
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• pp.127-158
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• 2015

This study analyzes the factors affecting user resistance to ERP in Vietnam, including the factors related to the cultural values of the users, which is rarely dealt in the previous ERP research. A research model is developed based on Klaus and Blanton [2010] and Hofstede [2011], consisting of the independent variables ('cultural value', 'system', 'organization', and 'process' related variables), a dependent variable ('user resistance to ERP') and a moderating variable ('self efficacy'). Major results of study include (1) users with high degree of uncertainty avoidance and femininity regard ERP as potential threat to their job and are likely to resist to ERP; (2) By training the users with high level of femininity to enhance their self efficacy, the degree of resistance to ERP can be reduced; (3) For ERP to be utilized successfully, systems should be developed in such a way in which working with ERP is not regarded as complex and difficult; and (4) communication and training play an important role in reducing the resistance of users.