• Journal of the Korean association of regional geographers
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• v.11 no.6
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• pp.517-529
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• 2005

Mt. Apsan is well known to be one of the most popular tourist sites around Daegu. Annually, more than 16 million persons visit Mt. Apsan. Although, in the mountain there are varieties of geomorphic and geological resources, there has been less concern to utilize the resources for geo-tourism. For example, there are about 10 valleys within Mt. Apsan and various landforms are scattered around the valleys. In this context, this study, based on field surveys centering around Gosangol valley, Anjiranggol valley and Dalbigol valley, focuses on exploring ways towards developing Mt. Apsan as an example geo-tourist site. The main findings are as follows: 1) The main landforms of Mt. Apsan include river cliff, cavern, free face, mud crack, ripple mark, fold, sheeting joint, talus, alluvial fan, pot hole, fault line, gnamma, columnar joint and metamorphic rock. 2) The guide notes on the landforms are developed. 3) In order to raise a learning effect of visitors on geomorphic resources, 9 nature trails are designed according to valleys and the length of visitor's stay.

• Journal of Digital Convergence
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• v.18 no.3
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• pp.299-304
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• 2020

In the past, commercial advertisements were produced mainly by advertisements that introduced functions, descriptions, or brands that the product had. However, the current advertising market appeals to the product by projecting emotion into the product in line with the consumer's expanded role of storytelling. Nudge effects can help you make the right choice in an economic and behavioral sense. Storytelling, which includes these nudge effects, allows people to communicate with people, thereby allowing consumers and businesses to move in the direction they want. This study understands the concept of nudge effect through commercial advertisement of Seoul Milk and studies the impact of corporate commercial advertisement on the analysis of the interactions between nudge effect and storytelling on the company's perception change as a consumer. The purpose of this study is to study the influence of the nudge effect. The results of this study have affected the perception of the entity, affected by the ripple effect of the nudge effects.

• Journal of Power Electronics
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• v.16 no.3
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• pp.1209-1217
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• 2016

This paper presents a novel charge pump scheme that combines the advantages of Fibonacci and Dickson charge pumps to obtain 30 V voltage for display driver integrated circuit application. This design only requires four external capacitors, which is suitable for a small-package application, such as smart card displays. High-amplitude (<6.6 V) clocks are produced to enhance the gate drive of a Dickson charge pump and improve the system's current drivability by using a voltage-doubler charge pump with a pulse skip regulator. This regulation engages many middle-voltage devices, and approximately 30% of chip size is saved. Further optimization of flying capacitors tends to decrease the total chip size by 2.1%. A precise and simple model for a one-stage Fibonacci charge pump with current load is also proposed for further efficiency optimization. In a practical design, its voltage error is within 0.12% for 1 mA of current load, and it maintains a 2.83% error even for 10 mA of current load. This charge pump is fabricated through a 0.11 μm 1.5 V/6 V/32 V process, and two regulators, namely, a pulse skip one and a linear one, are operated to maintain the output of the charge pump at 30 V. The performances of the two regulators in terms of ripple, efficiency, line regulation, and load regulation are investigated.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.10
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• pp.1126-1135
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• 2007

This paper presents the varactor-tuned miniaturized hairpin tunable filter with a single control voltage. The previously proposed miniaturization method is a very straight-forward method to miniaturize a parallel coupled-line filter. In this paper, the miniaturized hairpin tunable filter is proposed with the constant ratio rule of that the capacitances of the each stage always have constant ratio without any dependency to miniaturized electrical length. To show the validity of the proposed method, a 3rd order 0.5 dB ripple Chebyshev fitter with a center frequency of 900 MHz and a fractional bandwidth(FBW) of 10 % was designed and fabricated. The fabricated filter was based on CER-10 substrate of Taconic Inc. with 1SV277 varactor diode of Toshiba Inc. The center frequency of the fabricated filter can be changed from 606 MHz to 944 MHz, 338 MHz with the control voltage from 0.5 V to 4 V. The insertion loss of the proposed filter is increased with the increment of the control voltage, and the filter characteristics are well reserved expect of slight change of the bandwidth with the various control voltage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.239-245
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• 2016

In this study, a 12 V PWM boost converter was designed with the optimal values of the external components of the power stage was well as the compensation stage for smart electronic applications powered by a battery device. The 12 V boost PWM converter consisted of several passive elements, such as a resistor, inductor and capacitor with a diode, power MOS switch and control IC chip for the control PWM signal. The devices of the power stage and compensation stage were designed to maintain stable operation under a range of load conditions as well as achieving the highest power efficiency. The results of this study were first verified by a simulation in SPICE from calculations of the values of major external elements comprising the converter. The design was also implemented on the prototype PCBboard using commercial IC LM3481 from Texas Instruments, which has a nominal output voltage of 12 V. The output voltage, ripple voltage, and load regulation with the line regulation were measured using a digital oscilloscope, DMM tester, and DC power supply. By configuring the converter under the same conditions as in the circuit simulation, the experimental results matched the simulation results.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.2
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• pp.58-67
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• 1995

The paper describes the variation of magnetic fields caused by the operation of induction motors. The measuring system consists of the self-integrating magnetic field sensor, amplifier, and active integrator. From the calibration experiments, the frequency bandwidth of the magnetic field measuring system ranges from 20[Hz] to 300[kHz] and sensitivity is 0.234(mV/$\mu\textrm{T}$]. The magnetic fields generated under steady state and starting operations of duction motor are recorded by the proposed measuring system, and the fast Fourier transformation(FFT) of the measured data is performed to analyze the harmonic components. A single pulsed magnetic field is strongly caused by direct starting the induction motor, and its peak value is greater than 5 times as compared with the steady state value. The long transient duration and high intensity originates from the large inductance and dynamic characteristic of the induction motor, During the steady state operation of induction motor, subharmonics of magnetic field components, which depend on the pole number of induction motor, are observed. The lower order power-line harmonics can be inferred from the voltage flicker and current ripple which are derived from the torque fluctuation of induction motor. In the case of the induction motor drived by inverter, the harmonics of magnetic field are much more than those caused by direct starting method and are found generally to increase with decreasing the driving frequency.

• Journal of Environmental Impact Assessment
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• v.33 no.1
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• pp.30-41
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• 2024

The way we work is changing significantly with the rapid development of digitaltechnology, and paper documents are being replaced by electronic documents. However, in accordance with the Enforcement Decree and Enforcement Regulation of the Environmental Impact Assessment Act, the environmental impact assessment report must submit a set number of paper reports to organizations related to the project, and about 42 years have passed since it was submitted as a paperreport. In 2022, the National Institute of Ecology introduced a system to review paperreports as electronic documents in line with the trend of digital transformation. The cost reduction and carbon emission reduction effects of electronic document review were analyzed for 1,398 environmental impact assessments submitted and reviewed in 2022. In addition, a satisfaction survey was conducted targeting type 1 environmental impact assessment companies that were directly affected, and a total of 134 people responded. As a result of analyzing the effect of reviewing electronic documents, costs are reduced by a total of 101,424,900 won per year and carbon emissions are reduced by about 59.7 tons. As a result of the satisfaction survey, 94.8% of the respondents said electronic documentreview was very helpful, and 4.5% said it was helpful. The effectiveness of electronic documentreview was high, with 94.8% of respondents saying it was helpful in economic terms and 91.8% saying it was helpful in reducing work hours. If electronic documents are reviewed through the revisions to the Enforcement Decree and Enforcement Regulation of the Environmental Impact Assessment Act, the implementation of electronic document review is expected to have a ripple effect across the country, not only reducing costs and carbon emissions, but also reducing administrative time and saving storage space. Rapid changes in law and administration are needed to adapt to the digital transformation era.