• 설비공학논문집
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• 제24권2호
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• pp.129-135
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• 2012

Performance of various temperature-dependent vapor-pressure equations with two adjustable parameters is assessed. These are Antoine, Miller, Zia-Thodos, Mejbri-Bellagi and other 10 equations. The equations are fitted to correlate the data from NIST Chemistry WebBook for 43 pure substance refrigerants from the critical point to the triple point. It was found that the Mejbri-Bellagi equation yields the lowest average absolute deviation of 0.37% compared with that of 0.58% of the Miller equation which is known to give better fit to experimental data than the Antoine equation(1.42%) does.

• Journal of the Optical Society of Korea
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• 제20권5호
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• pp.623-627
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• 2016

A power-adjustable fully-integrated CMOS optical receiver with multi-rate clock-and-data recovery circuit is presented in standard 65-nm CMOS technology. With supply voltage scaling, key features of the optical receiver such as bandwidth, power efficiency, and optical sensitivity can be automatically optimized according to the bit rates. The prototype receiver has −23.7 dBm to −15.4 dBm of optical sensitivity for 10⁻⁹ bit error rate with constant conversion gain around all target bit rates from 1.62Gbps to 8.1 Gbps. Power efficiency is less than 9.3 pJ/bit over all operating ranges.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.29-31
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• 1996

Industry today utilizes adjustable-speed drives for a variety of application. This paper will present general Guidelines to optimize selecting the drive or drive system for the needs of the application and introduce the user to the many items that must be covered by such industry standards in order to assure successful applications on ADS.

• 분석과 대안
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• 제4권1호
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• pp.105-123
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• 2020

This study analyzes the risk selection behavior of Japanese households. The study approaches the view of 'the hyperbolic discount' which is used in behavioral economics based on the rise in mortgage lending by low-income households in the late 2000s. The study focuses on how households risk preferences vary by income levels. The study analyzes the relationship of attitude of household interest rate risk using Binomial Logistic and Heckman two-step estimation method assuming that there are only two types of Adjustable-Rate Mortgage and Fixed-Rate Mortgage. As a result of the empirical analysis, low-income households annual income tend to have a higher proportion of housing debt as same as higher interest rate risk preferences households in proportion to income growth and interest rate risk preferences. Those results indicate that there is possibility of a hyperbolic discount on low-income households in Japan, and support the hypothesis that low-income households are relatively higher household debt ratio because of high utility due to home purchase in the near future (short-term).

• Steel and Composite Structures
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• 제46권1호
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• pp.107-114
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• 2023

A new intelligent adaptive control scheme was proposed that combines observer disturbance-based adaptive control and fuzzy adaptive control for a composite structure with a mass-adjustable damper. The most important advantage is that the control structures do not need to know the uncertainty limits and the interference effect is eliminated. Three adjustable parameters in LMI are used to control the gain of the 2D fuzzy control. Binary performance indices with weighted matrices are constructed to separately evaluate validation and training performance using the revalidation learning function. Determining the appropriate weight matrix balances control and learning efficiency and prevents large gains in control. It is proved that the stability of the control system can be ensured by a linear matrix theory of equality based on Lyapunov's theory. Simulation results show that the multilevel simulation approach combines accuracy with high computational efficiency. The M-TMD system, by slightly reducing critical joint load amplitudes, can significantly improve the overall response of an uncontrolled structure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1984년도 하계학술회의논문집
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• pp.38-40
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• 1984

• 대한전기학회:학술대회논문집
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• 대한전기학회 1985년도 하계학술회의논문집
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• pp.52-54
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• 1985

• 대한전기학회:학술대회논문집
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• 대한전기학회 1985년도 하계학술회의논문집
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• pp.41-43
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• 1985

• 한국산학기술학회논문지
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• 제16권12호
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• pp.8901-8907
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• 2015

기존의 가로등은 배광특성 조절이 어려워 주변 환경 및 도로의 상황에 따라 빛을 고루 전달하지 못하므로, 눈부심, 농작물 결실저해 및 수면 방해 등의 광공해를 발생시키고 있는 실정이다. 본 논문에서는 이러한 문제를 해결하기 위해 주변 환경 및 도로 상황에 따라 조사되는 빛의 각도를 조절할 수 있는 새로운 구조의 LED 가로등 기구를 제안 하였다. 제안된 LED 가로등 기구는 반원구조의 형상을 갖는 각도 조절 장치를 이용하여 도로의 종류 및 특성에 따라 배광특성을 조절 할 수 있도록 하였다. 측정 및 모의실험결과 배광각도는 최소 $100^{\circ}$에서 최대 $154^{\circ}$까지 조절이 가능함을 확인하였고, 평균조도는 KS 규정의 15%를 초과하였으며, 종합 균제도는 KS 규정의 50% 이상을 초과하여 성능이 우수함을 확인할 수 있었다. 따라서 본 연구를 통하여 개발된 대용량 LED 가로등 기구는 광공해를 해소하고 광원 분포의 균제도 최적화와 눈부심을 최소화 할 수 있을 것으로 사료된다.

• 한국산학기술학회논문지
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• 제13권12호
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• pp.5669-5675
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• 2012

이종궤간(표준줴/광궤)이 존재하는 유라시아 철도네트워크(TKR, TCR 및 TSR)의 화물운송시간 및 비용을 절감하기 위해서는 이 구간을 자유롭게 운행할 수 있는 궤간가변 윤축시스템의 개발이 중요하다. 국내에서는 기존 해외 윤축시스템을 보완하고자 새로운 한국형 궤간가변 윤축시스템을 개발 및 제작중이다. 본 연구에서는 안전-수명설계관점에서 강도와 내구성해석을 수행하였다. 본 시스템의 내구성해석결과로서, 주요부품은 $1{\times}10^7$ 사이클까지 안전하였다. 또한, 주행중 안전성을 확인하기위하여 국제철도규정 UIC에 따라 리그피로시험을 수행하였다. 이 시험을 통하여 본 궤간가변 윤축시스템은 관련 안전규정에 만족함을 확인하였다.