• Journal of Korea Society of Industrial Information Systems
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• v.28 no.1
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• pp.1-8
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• 2023

In this paper, we developed a mid-range automotive radar systems based on the performance requirements and test procedures of the intelligent transport systems, that is lane change decision aid systems (LCDAS). The mid-range automotive radar has the maximum detection range up to 80m and an update time within 50ms. The computational loads of a signal processing were reduced by using ROI preprocessing technique. Considering actual driving environments, radar performance evaluations were conducted in two driving scenarios at an automotive proving ground.

• Journal of Engineering Education Research
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• v.25 no.3
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• pp.11-25
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• 2022

The purpose of this study is to propose a strategy model for engineering education for citizen through the connection between colleges of science and engineering and science museums as a way to achieve citizen science. For this model, the role of universities was redefined as social contributions through engineering education from the perspective of knowledge triangle and university entrepreneurship. In addition, the science museum was re-examined as an engineering education platform and selected as an institution that supports the contribution of colleges to society. For practical model development, the connection types of these two institutions were analyzed as case studies and interview to collect opinions from experts in the science museum. In this process, convergence education content development, reinforcement of college-science museum linkage, infrastructure construction, development of college resource utilization plans, and maintenance and expansion of educational programs diversification were derived as components for model development. Based on this, engineering education model for citizen was presented that matches educational programs according to the type of participation of colleges including key factors and considerations.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.1
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• pp.93-97
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• 2023

A triboelectric nanogenerator (TENG) is a device that converts mechanical energy into electrical energy, and has been considered as a substitute for continuous power supply due to its high performance, simple structure and eco-friendliness. Recently, it is important to develop a TENG using a non-toxic material in order to use it as a power source for wearable, attachable, and body-embeddable electronics. Here, we developed a human friendly TENG using polyvinyl chloride (PVC) gel containing acetyl tributyl citrate (ATBC), a non-toxic plasticizer. PVC gels were fabricated using various ratios of PVC and ATBC, and optimized by investigating dielectric properties, surface potential, output performance, and durability. The PVC gel based TENG generates output signals of 73 V and 4.3 μA, i.e., a 5-fold enhancement in the output power compared to pristine PVC-based TENG. In addition, the PVC gel can be stretched over 500% of strain. This study is expected to be helpful in the future development of non-toxic wearable TENG.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.470-473
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• 2021

In this study, we developed the biometric ultrasound transducer, residual thickness measurement algorithm and optimized ultrasound operation methods to diagnose precise conditions of implanted medical prosthetic material inserted during total hip artificial joint replacement. In detail, ultrasound transducers having 8 MHz and 20 MHz center frequencies with similar sensitivity and bandwidth were fabricated to measure various thicknesses of commercial polyethylene-based artificial hip liners, resulting in a comparative analysis of signal-to-noise ratio and axial resolution to conduct an optimization study of ultrasound operations in vivo.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.194-196
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• 2022

최근 대기 오염이 심각해지면서 이와 관련된 다양한 환경 문제가 발생하고 있다. 이러한 대기 오염에 대비하기 위해서 본 논문에서는 대기 오염 데이터를 수집하고 LiDAR 카메라를 활용하여 사각 지역에서 대기 오염을 측정하는 서비스를 제안한다. 이를 위해 대기 오염 데이터의 모니터링과 LiDAR 카메라를 활용할 수 있는 장치를 구축한다.

• Bulletin of the Korean Chemical Society
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• v.19 no.4
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• pp.434-436
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• 1998

The mechanism of nucleophilic displacement was studied by using three variable systems of ${\rho}_X,\; {\rho}_Y,\; and {\rho}_Z$ obtained from the change of substituent X, Y, and Z for the reaction of (Z)-substituted benzyl (X)-benzensulfonates with (Y)-substituted thiobenzamides in acetone at 45 ℃. The results ${\rho}_Z$<0 and ${\rho}_YZ$>${\rho}_XZ$ indicate that this reaction series proceeded via a dissociative $S_N2$ mechanism. The prediction of the movement of TS by using the sign of ${\rho}_XZ{\cdot}{\rho}_{YZ}$ accorded with the Hammond postulate.

• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.557-557
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• 2019

• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.558-558
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• 2019

• Journal of the Korean Regional Science Association
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• v.32 no.1
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• pp.27-49
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• 2016

This study examines the effects of real exchange rate (RER) depreciation shocks on firm-level productivity and employment in Daegu-Gyeongbuk manufacturing industries during 2006-2012. In particular, the study focuses on a sharp and persistent RER depreciation of the Korean Won from 2007 to 2009, which is a situation akin to a natural experiment in Korea. We find that RER depreciation has positive effects on productivity for firms with high export exposure in foreign markets. However, these effects disappear when RER depreciation persists. In addition, we do not find evidence that RER depreciation affects employment of Daegu-Gyeongbuk firms significantly. Firms in Daegu-Gyeongbuk region should pursue core competency to obtain international competitiveness rather than depending on temporary better price condition driven by RER depreciation. Further, policy makers in a local government should provide firms with financial and investment support to encourage innovation and R&D.

• Journal of the Korean Electrochemical Society
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• v.25 no.4
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• pp.134-153
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• 2022

Regardless of a trade-off relationship between energy density and safety, it is essential to improve both properties for future lithium secondary batteries. Especially, to improve the energy density of batteries further, not only thickness but also weight of separators including ceramic coating layers should be reduced continuously apart from the development of high-capacity electrode active materials. For this purpose, an attempt to replace conventional slurry coating methods with a deposition one has attracted much attention for securing comparable thermal stability while minimizing the thickness and weight of ceramic coating layer in the separator. This review introduces state-of-the-art technology on ceramic-coated separators (CCSs) manufactured by the deposition method. There are three representative processes to form a ceramic coating layer as follows: chemical vapor deposition (CVD), atomic layer deposition (ALD), and physical vapor deposition (PVD). Herein, we summarized the principle and advantages/disadvantages of each deposition method. Furthermore, each CCS was analyzed and compared in terms of its mechanical and thermal properties, air permeability, ionic conductivity, and electrochemical performance.