• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.5
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• pp.105-112
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• 2017

In this study, plastics were deformed after molding due to the characteristics of the material. The Taguchi experimental design method was utilized to find the molding conditions that minimized deformation of the plastic bezel to be assembled in an automotive steering wheel. The injection molding conditions applied to the experimental design method are the melt temperature, cavity plate coolant temperature, core plate coolant temperature, and cooling time. Each condition was divided into five levels, and a total of 25 experiments were planned. However, instead of performing 25 actual molding experiments, the injection molding analysis was performed using the Moldflow program, and the deformation values for each molding analysis were obtained. The optimal molding conditions were obtained from these deformation values. The actual injection molding experiment using optimal molding conditions was compared with the deformation amount of the current molded product. The deformation was measured using a precise 3D scanner. The deformation amount of the molded product under optimal molding conditions was 16.1% lower than the deformation amount of the current molded product.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.871-876
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• 2011

In this paper, a voltage-controlled frequency tunable current-mode integrator and a 3rd-order current-mode Chebyshev filter in 1.8V-$0.18{\mu}m$ CMOS is realized for software radio applications in system-on-chips. This filter is used for reconstruction purposes between a current-steering DAC and a current-mode mixer. Power consumption of the designed filter can be reduced by using a current-mode small size integrator. And also, cutoff frequency of this filter is variable between 1.2MHz and 10.1MHz, the power consumption is 2.85mW. And the voltage bias compensated circuit is used to control the voltage variation.in the designed filter.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.1-9
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• 2008

The current test methods are insufficient to evaluate and ensure the safety and reliability of vehicle system for all possible dynamic situation including the worst case such as rollover, spin-out and so on. Although the known NHTSA J-turn and Fish-hook steering maneuvers are applied for the vehicle performance assessment, they aren't enough to estimate other possible worst case scenarios. Therefore, it is crucial for us to verify the various worst cases including the existing severe steering maneuvers. This paper includes the procedure to search for other useful worst case based upon the existing worst case scenarios mentioned above and its application in simulation basis. The only human steering angle is selected as a design parameter here and optimized to maximize the index function to be expressed in terms of either roll angle or yaw rate. The obtained scenarios were enough to generate the worst case to meet NHTSA worst case definition (ex.2-inch wheel lift). Additionally, as an application, the worst case steering maneuver is acquired for the vehicle to operate with a simple ESP system. It has been concluded that the new procedure in this paper is adequate to create other feasible worst case scenarios for a vehicle system both with an intelligent safety control system and without it.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.179-184
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• 2012

Environmental impact is getting more attention in many feasibility studies for railroad-related projects and research items. For sustainable growth and green transportation, the benefits typically used for feasibility studies in railway-related projects, are composed mostly of economic criterions which is not considering growing attention on changing paradigm. Based on the analysis of current methodologies, improvements in estimating environmental impact especially on noise and pollution are suggested. Active steering bogie has been proposed to satisfy stabilizing and steering performance of railroad. This paper describes the feasibility study of the active steering bogie for a urban railway vehicle based on environment-related criteria.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.4
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• pp.160-165
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• 1998

In this paper, We discuss the directional stability of a Mini-bus with varying suspension design parameters. We analyzed the vehicle behavior during the cornering in a transient steering condition. We made a vehicle model by use of DADS, which is dynamic analysis software, in order to carry out many cases of simulation with varying design parameters. The effect of toe-geometry change to vehicle stability is evaluated by computer simulation and the actual test. In order to reduce the under steer characteristics of a mini-bus, the amount of toe geometry change should be less than current value.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.3
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• pp.51-57
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• 2010

A dual-mode direct conversion receiver is developed in $0.13\;{\mu}m$ RF CMOS process for IEEE 802.11n based wireless LAN and IEEE 802.16e based mobile WiMAX application. The RF receiver covers the frequency band between 2.3 and 2.7 GHz. Three-step gain control is realized in LNA by using current steering technique. Current bleeding technique is applied to the down-conversion mixer in order to lower the flicker noise. A frequency divide-by-2 circuit is included in the receiver for LO I/Q differential signal generation. The receiver consumes 56 mA at 1.4 V supply voltage including all LO buffers. Measured results show a power gain of 32 dB, a noise figure of 4.8 dB, a output $P_{1dB}$ of +6 dBm over the entire band.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.3
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• pp.77-101
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• 2022

In this study, the current status of the public library steering committee, which is operated in accordance with Article 30 Paragraphs 2 and 3 of the Libraries Act, was examined and understood through a survey, and the direction of the promotion and policy for revitalizing the steering committee was sought moving forward. As a result of the analysis performed, the number of operations is once or twice a year, and the decisions of the steering committee meetings are reported to their supervisors, yet the reporting and disclosure of the meeting minutes are not mandatory in terms of regulations, etc., and while the importance was recognized, it turned out that the operation was carried out formally due to the lack of personnel in charge. The primary factors for revitalizing the operation were investigated as the structure of the committee, the responsibilities and authority of the committee, and the assignment of dedicated staff, etc. While there was a high perception that the enactment of a standard ordinance (proposal) was necessary, the concerns about the inhibition of autonomy were also mentioned, and hence, it is necessary to enact a standard ordinance(proposal) that sufficiently guarantees autonomy. To revitalize the steering committee, it is necessary to find various utilization and operational plans by considering holding regular meetings, supplementing systems and regulations that can reflect meeting decisions, establishing subcommittees, and assigning dedicated staff.

• Journal of Information Display
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• v.9 no.3
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• pp.1-7
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• 2008

With the aim of creating a high-quality display system with value-added functions, we designed a current mode multiplexer for LTPS TFT devices. The multiplexers had less than 1 volt logic swing, and speed improvement was evident compared with that of conventional CMOS architecture. We refined the multiplexer to achieve a more stable current steering operation. By using the versatility of the multiplexer, a new NAND/AND and NOR/OR logic gates were designed through the simple modification of signal connections. Two micron LTPS TFT parameters were used during the HSPICE simulation of the circuits.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.10
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• pp.39-45
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• 2011

This paper proposes a low power current-steering 10-bit DAC selecting clock enable signal. The proposed DAC reduces the clock power by cutting the clock signal to the current-source cells in wihich the data will not be changed. The proposed DAC was implemented using a 0.13${\mu}m$ CMOS process with $V_{DD}=1.2V$. Its core area is 0.21$mm^2$. It consumes 4.46mW at 1MHz signal frequency and 200MHz sampling rate. The clock power is reduced to 30.9% and 36.2% of a conventional DAC at 1.25MHz and 10MHz signal frequencies, respectively. The measured SFDRs are 72.8dB and 56.1dB at 1MHz and 50MHz signal frequencies, respectively.

• Journal of IKEEE
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• v.21 no.4
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• pp.331-337
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• 2017

In this paper, we present the design of a 20MHz bandwidth 3rd-order continuous-time low-pass sigma-delta modulator with low-noise and low-power consumption. The bandwidth of the system is sufficient to accommodate LTE and other wireless network standards. The 3rd-order low-pass filter with feed-forward architecture achieves the low-power consumption as well as the low complexity. The system uses 3bit flash quantizer to provide fast data conversion. The current-steering DAC achieves low-power and improved sensitivity without additional circuitries. Cross-coupled transistors are adopted to reduce the current glitches. The proposed system achieves a peak SNDR of 65.9dB with 20MHz bandwidth and power consumption of 32.65mW. The in-band IM3 is simulated to be 69dBc with 600mVp-p two tone input tones. The circuit is designed in a 0.18-um CMOS technology and is driven by 500MHz sampling rate signal.