• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.150-152
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• 2004

The battery charge/discharge process, the final step of the secondary battery production process, requires real-time precision controls for improving both lifetime and performance of the battery cell. In this paper, we present embedded system design for precision control of the secondary battery charge/discharge production process using low power embedded processor based on embedded linux. This system receive charge/discharge command from the main server through ethernet. Compared to existing charge/discharge control system, our design makes low cost and precision control system possible.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.367-376
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• 2016

This paper presents a cell balancing method for a single switch flyback converter with a multi-winding transformer. The conventional method using a flyback converter with a multi-winding transformer is simple and easy to control, but the voltage of each secondary winding coil might be non-uniform because of the unequal effective turn-ratio. In particular, it is difficult to control the non-uniform effect using turn-ratios because secondary coil has a limited number of turns. The non-uniform secondary voltages disturb the cell balancing procedure and induce an unbalance in cell voltages. Individual cell control by adding a switch for each cell can reduce the undesirable effect. However, the circuit becomes bulky, resulting in additional loss. The proposed method here uses the conventional flyback converter with an adjustment made to the output filters of the cells, instead of the additional switch. The magnitude of voltage applied to a particular cell can be reduced or increased according to the adjusted filter and the selected switching frequency. An analysis of the conventional converter configuration and the filter design method reveals the possibility of adequate cell balancing control without any additional switch on the secondary side.

• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1554-1560
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• 2019

Development of digital main control rooms (MCRs) has greatly changed operating environments by altering operator tasks, and thus the unique characteristics of digital MCRs should be considered in terms of human reliability analysis. Digital MCR tasks can be divided into primary tasks that directly supply control input to the plant equipment, and secondary tasks that include interface management conducted via soft controls (SCs). Operator performance regarding these secondary tasks must be evaluated since such tasks did not exist in previous analog systems. In this paper, we analyzed SC-related tasks based on simulation data, and classified the error modes of the SCs following analysis of all operational tasks. Then, we defined the factors to be considered in human reliability analysis methods regarding the SCs; such factors are mainly related to interface management and computerized operator support systems. As these support systems function to reduce the number of secondary tasks required for SC, we conducted an assessment to evaluate the efficiency of one such support system. The results of this study may facilitate the development of training programs as well as help to optimize interface design to better reflect the interface management task characteristics of digitalized MCRs.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.4
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• pp.223-231
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• 2015

Enclosures are widely used to alleviate the contribution of machinery noise. It has been long concerned with the noise transmission through the access openings of the enclosures. In this study, we investigate active noise control technology for reduction of the transmission. A numerical model based on the acoustic boundary element method is first established. Using the numerical model, the acoustic transfer functions of the field points over the opening to the primary source at arbitrary locations are estimated. The feedforward control to minimize the acoustic power through the opening is then numerically implemented. The controller drives the secondary source to destructively interfere the noise transmission through the opening. Finally, a parametric study is conducted to evaluate the effects of the location and the number of the microphones on the control performance. Furthermore, the effects of the location of the secondary source on the performance of active noise control are investigated. It is followed that the control system implemented in this study leads to a significant reduction of about 31.5 dB in the sound power through the opening using only one secondary source located at the optimized position.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.796-802
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• 2013

In this study, we investigates active control technology to reduce the noise transmitted to the outside through the opening of enclosures. A numerical model based on acoustic boundary element method is first established. Using the numerical model, the acoustic transfer functions of the field points over the opening to the primary source at arbitrary locations are estimated. The feedforward control to minimize the acoustic power through the opening is then numerically implemented. The controller generates the secondary source to destructively interfere the noise transmission through the opening. Finally, a parametric study is conducted to evaluate the effects of the location and the number of the microphones on the control performance. Furthermore, the effects of the location of the secondary source on the performance of active noise control are investigated. It is followed that the control system implemented in this study leads to a significant reduction of about 35dB in sound power through the open using only on secondary source located at the optimized position.

• Korean Security Journal
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• no.22
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• pp.231-258
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• 2010

A study apartment house inhabitants of to, crime prevention effort is done satisfaction analysis and that deduce design plan of CPTED that can overcome safe life space embodiment and criminal fear from crime in Juminin viewpoint through atomize group's interaction by background fantast. Is positive because factor analysis wave and satisfaction index of deduce universe (Total group) 8 factor are presented more than all 0, and quite was expose by level that is worth accommodating. Satisfaction index of The secondary design group (Group1) 8 factor is positive because is presented more than all 0, and mechanical access control, mechanical surveillance is level that is worth accommodating quite, and level that is proper in remainder 6 dimension appear. Can know that 1 The secondary design group(Group2) is expose by level that satisfaction characteristic of 8 factor can be presented more than all 0 and appeared positively, and accommodate quite in all dimensions. Result that analyze Two-way ANOVA satisfaction difference of environment design of group by satisfaction of the primary and the secondary design group is high in 8 all dimensions of CPTED, and satisfaction by appeared satisfaction high in group less than natural access control, 2 years of natural surveillance, and reciprocal action effect that go with group is high satisfaction in 2 years low in The secondary design group more than the primary and the secondary design group of systematic access control and natural access control, and the primary and the secondary design group appeared high in subgroup of 2 remainders. Satisfaction difference by group by crime prevention effort satisfaction of the primary and the secondary design group is high in 8 all dimensions of CPTED, and satisfaction difference by crime prevention effort appeared satisfaction high in 'A prize' group to The secondary design group, and reciprocal action efficiency is high in 'A prize' group in The secondary design group more than the primary and the secondary design group in mechanical access control, systematic access control, natural access control, territoriality reinforcement, and satisfaction of 'Between' and 'Very' group appeared high in the primary and the secondary design group.

• Journal of the speleological society of Korea
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• no.8
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• pp.11-18
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• 1998

The mineral hydroxyapatite is very common species in secondary phosphates originating from guanos(HILL et at., 1997). Several mineralogical analyses of spelean hydroxyapatite exist(e.g., KASHIMA, 1968, 1979 ; MAKI et at., 1977 ; SUH et at., 1978 ; WANG, 1982 a, b), whereas detailedeochemical composition of secondary hydroxy apatites has not been reported in Japan.(omitted)

• Journal of Korean Neurosurgical Society
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• v.29 no.1
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• pp.66-71
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• 2000

Objective : There are many treatment modalitis in management of idiopathic trigeminal neuralgia. In the secondary trigeminal neuralgia, there has been only sporadic reports of the etiology. Authors report the treatment result of secondary trigeminal neuralgia with percutaneous radiofrequency rhizotomy. Methods : During last ten years, 129 trigeminal neuralgias were treated by percutaneous radiofrequency(RF) rhizotomy by authors. Among them, nine patients were secondary trigeminal neuralgias. These patients refused treatment for the primary cause and only wanted pain control. The offending lesions were three arachnoid cysts, six tumors. The mean age was 47.8 years and the mean duration of follow-up was 6.2 years. The right V2,3 distribution was most prevalent area of pain. Authors used the conventional Hartel's anterior approach and straight electrode for RF lesion generation. Result : The early result was satisfactory. Eight of nine patients became free of pain and one patient needed minimal dose of carbamazepine. The overall pain control was 100%. There was no mortality or morbidity for initial RF rhizotomy. During follow-up, four patients showed recurrence of pain(44%). Among these, two underwent repeated RF rhizotomy and became free of pain. The other two were controlled with medical management. Conclusion : These results indicate that the percutaneous RF rhizotomy is effective means of pain control. Overall recurrence was somewhat higher than that of idiopathic trigeminal neuralgia. Even with recurrence, however, repeated RF rhizotomy seems to be effective method of control of pain in these cases.

• Geomechanics and Engineering
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• v.7 no.3
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• pp.279-295
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• 2014

A series of one-dimensional consolidation tests and triaxial creep tests were performed on Nansha clays, which are interactive marine and terrestrial deposits, to investigate their time-dependent behaviour. Based on experimental observations of oedometer tests, normally consolidated soils exhibit larger secondary compression than overconsolidated soils; the secondary consolidation coefficient ($C_{\alpha}$) generally gets the maximum value as load approaches the preconsolidation pressure. The postsurcharge secondary consolidation coefficient ($C_{\alpha}$') is significantly less than $C_{\alpha}$. The observed secondary compression behaviour is consistent with the $C_{\alpha}/C_c$ concept, regardless of surcharging. The $C_{\alpha}/C_c$ ratio is a constant that is applicable to the recompression and compression ranges. Compared with the stage-loading test, the single-loading oedometer test can evaluate the entire process of secondary compression; $C_{\alpha}$ varies significantly with time and is larger than the $C_{\alpha}$ obtained from the stage-loading test. Based on experimental observations of triaxial creep tests, the creep for the drained state differs from the creep for the undrained state. The behaviour can be predicted by a characteristic relationship among axial strain rate, deviator stress level and time.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.116-121
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• 2011

Performance of Secondary Injection Thrust Vector Control system is investigated under various secondary injection operating conditions. 3-dimensional converging-diverging nozzle having 8 secondary injection nozzles is used in this numerical study. Total pressure of flow inside the nozzle is about 70bars, and total temperature set to 300K for cold flow simulation. Effect of secondary injection flow rate and injection nozzle configuration is considered in this research. Simulation is conducted with commercial CFD code Ansys Fluent v13. Spalart-Allmaras(1-equation)model is used for turbulence modeling with AUSM+ scheme. Various performance factors as Axial thrust, side force, system specific impulse ratio are considered and explained for system performance evaluation.