• 한국통신학회논문지
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• 제18권11호
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• pp.1663-1668
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• 1993

단일종단 저역통과 필터의 설계이론을 기초로 비대칭으로 결합된 마이크로스트립 선로를 사용하여 X-band용 인접대역 다이플랙서를 실현시켰다. 중심주파수 9,11 GHz에서 채널 1과 2의 대역폭을 각각 22%와 18%로 설계하였고 SuperCompack을 이용하여 최적화하였다. 측정결과 통과 대역폭과 인접하는 채널의 차단대역에서 감쇄특성은 설계값과 잘 일치하였으나 삽입손실에서 0.5dB 정도의 차이가 있었다.

• 한국태양광발전학회지
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• 제3권2호
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• pp.63-69
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• 2017

New and renewable energy has attracted a significant attention since the Paris Agreement in 2015. Especially hydrogen energy is important for reducing greenhouse gas produced during transportation. The new government suggested that the eco-friendly vehicles, hydrogen infrastructure and the development of new and renewable energy are the major growth engines in the future. Hydrogen energy is also concerned as the main part of our economy in the national affairs. In the policy of Mission Innovation Strategy and the third Eco-Friendly Vehicle Master Plan, government presents the status, future direction, technical road map and distribution road map of hydrogen energy. With this trend, investments in the research and development on hydrogen and fuel cells have expanded and will continue to expand for the implementation of the policy. The cost reduction, technical innovation and the increase in the localization rate are required for the new and renewable energy, including hydrogen energy, to become the future growth engine.

• 한국조명전기설비학회지:조명전기설비
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• 제6권1호
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• pp.40-48
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• 1992

In this paper, th technique of particular harmonics elimination in three-phase PWM Inverter is discussed. And voltage control technique is derived whereby harmonics elimination is possible in variable voltage variable frequency three-phase I.M.. The required switching patterns are determined on Personal Computer and the results are stored in look-up table in EPROM for controlling the switching of the PWM Inverter. The results show that experiments are in good agreement with simulation based on the theory.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2000년도 제13회 춘계학술대회 및 임시총회 학술발표 논문집
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• pp.1084-1088
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• 2000

현재 인터넷에서 QoS(Quality of Service )를 보장하기 위해 다양한 메커니즘이 제안되고 있다. 통신망에서 QoS를 지원하기 위해서는 해당 응용 서비스마다 적절한 자원을 할당하고 자원 사용을 모니터링 및 제어하며, 이례적인 사건이 발생하였을 경우 자원을 재할당할 수 있도록 지원하는 자원관리 기능이 요구된다. 본 논문에서는 차등서비스를 제공하는 인터넷에서 QoS를 제공하기 위해 망자원을 관리 및 제어하는 정책기반 자원관리시스템의 설계 및 구현에 대해 기술한다. 정책기반 자원관리 시스템은 도메인 내의 사용자나 망 관리자로부터 QoS 요구를 받으면 도메인 내의 자원사용량과 자원사용정책에 따라서 내부자원을 할당하고, 이웃도메인과는 QoS가 보장되도록 SLA(Service Level Agreement)를 체결하는 기능을 수행한다. 구현한 정책기반 자원관리시스템은 정책정보를 PIB(Policy Information Base)의 형태로 정책 데이터베이스에 저장하며, 정책서버와 정책 클라이언트 사이에는COPS(Common Open Policy Service)프로토콜을 사용하여 정책 정보를 송수신함을 특징으로 한다.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.732-740
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• 2022

A piping system stress analysis need to be re-performed for structural integrity assessment after reinforcement of a pipe with significant wall thinning. For efficient stress analysis, a one-dimensional beam element for the wall-thinned pipe with reinforcement needs to be developed. To develop the beam element, this work presents analytical equations for elastic stiffness of the wall-thinned pipe with reinforcement are analytically derived for axial tension, bending and torsion. Comparison with finite element (FE) analysis results using detailed three-dimensional solid models for wall-thinned pipe with reinforcement shows good agreement. Implementation of the proposed solutions into commercial FE programs is explained.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 가을 학술발표회논문집
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• pp.16-23
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• 1993

The new p-version crack model is proposed to estimate the bending stress intensity factors of the thick cracked plate under flexure. The proposed model is based on high order theory and $C^{\circ}$-plate element including shear deformation. The displacements fields are defined by integrals of Legerdre polynomials which can be classified into three groups such as basic mode, side mode and internal mode. The computer implementation allows arbitrary variations of p-level up to a maximum value of 10. The bending stress intensity factors are computed by virtual crack extention approach. The effects of ratios of thickness to crack length(h/a), crack length to width(a/W) and boundary conditions are investigated. Very good agreement with the existing solution in the literature are shown for the uncracked plate as well as the cracked plate.

• 대한수학회논문집
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• 제39권2호
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• pp.547-562
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• 2024

By utilizing coupling the strategy in the 5D Sprott B system, a new no equilibrium 7D hyperchaotic system is introduced. Despite the proposed system being simple with twelve-term, including solely two cross product nonlinearities, it displays extremely rich dynamical features such as hidden attractors and the dissipative and conservative nature. Besides, this system has largest Kaplan-Yorke dimension compared with to the work available in the literature. The dynamical properties are fully investigated via Matlab 2021 software from several aspects of phase portraits, Lyapunov exponents, Kaplan-Yorke dimension, offset boosting and so on. Moreover, the corresponding circuit is done through Multisim 14.2 software and preform to verify the new 7D system. The numerical simulations wit carryout via both software are agreement which indicates the efficiency of the proposed system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.476-482
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• 2011

Following public expectations from the emergence of an international agreement with greater legal force after the expiration of the 2012 Kyoto Protocol, Korea is also making efforts to effectively and systematically initiate the mitigation policy and enforce the terms of the international climate change agreement. The majority of domestic industries are candidates for greenhouse gas emission regulation, thereby requiring the proposal of a method that effectively reduces environmental contaminate substances released from railway facilities, following the prediction of an increase in railway usage as an environment-friendly transportation method in the future. Accordingly, this study has quantitatively calculated the amount of released environmental contaminates through the life cycle assessment (LCA) on railway facility constructions, and has evaluated the environmental load and the amount of greenhouse gas emissions through the resulting values. The results of the LCA analysis showed that the amount of environmental load was the highest at the early stages of material implementation and construction, and that the value of global warming was viewed as the highest among the effects. As officially announced by the World Meteorological Organization and the United Nations Environment Program that $CO_2$ is the main culprit of global warming, the analytical values confirmed that the amount of $CO_2$ emissions accounted for more than half of the released greenhouse gases at 2.90E+04tons. The environmental load and $CO_2$ emission rates analyzed in this study are judged to be used in the deduction of the optimum environment-friendly method and quantitative environmental effect of railway facility constructions in the future, as the values can be evaluated based on their degree of environment friendliness.

• 전기학회논문지P
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• 제59권1호
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• pp.58-63
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• 2010

In this paper, we proposed a wearable respiration measurement system with textile capacitive pressure sensor. Belt typed textile capacitive pressure sensor approach of respiration measurement, from which respiration signatures and rates can be derived in real-time for long-term monitoring, are presented. Belt typed textile capacitive pressure sensor has been developed for this measurement system. the distance change of two plates by the pressure of motion has been used for the respiration measurement in chest area. Respiration rates measured with the textile capacitive pressure sensor was compared with standard techniques on 8 human subjects. Accurate measurement of respiration rate with developed sensor system is shown. The data from the method comparison study is used to confirm theoretical estimates of change in capacitance by the distance change. The current version of respiratory rate detection system using textile capacitive pressure sensor can successfully measure respiration rate. It showed upper limit agreement of $3.7997{\times}10^{-7}$ RPM, and lower limit of agreement of $-3.8428{\times}10^{-7}$ RPM in Bland-Altman plot. From all subject, high correlation were shown(p<0.0001). The proposed measurement method could be used to monitor unconscious persons, avoiding the need to apply electrodes to the directly skin or other sensors in the correct position and to wire the subject to the monitor. Monitoring respiration using textile capacitive pressure sensor offers a promising possibility of convenient measurement of respiration rates. Especially, this technology offers a potentially inexpensive implementation that could extend applications to consumer home-healthcare and mobile-healthcare products. Further advances in the sensor design, system design and signal processing can increase the range and quality of the rate-finding, broadening the potential application areas of this technology.

• 성인간호학회지
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• 제12권2호
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• pp.278-285
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• 2000

Nausea, vomiting and retching are universal symptoms that affect individuals' state of health and self-care activities of individuals. Accurate measurements of individual symptoms are required to gather more definitive data, and enhance understanding, planning, and implementation of self-care actions. Recently the Rhodes Index of Nausea, Vomiting, and Retching(INVR), a new format of the INV-2(the Rhodes Index of Nausea and Vomiting), was developed to measure the symptoms of nausea, vomiting and retching in an English speaking population. To determine the reliability and validity of the INVR, and the possibility of using the instrument in Korea, the Korean translation of the INVR and the INV-2 were administered to a convenient sample of 105 patients at two University Hospitals in Kwangju, Korea. The Cronbach's alpha to estimate the internal consistency of reliability for INVR was 0.844. Equivalent measures of reliability were conducted to determine the percentage of agreement and the Spearman rank correlation coefficients for responses on the two instruments. The percent agreement was 83% and the correlation coefficient was 0.906 over all. A significant differences between the INVR scores of the patients with and without nausea, vomiting, or retching were seen, which indicated a construct validity. The INVR was found to be more user friendly for the patient and the healthcare providers. As a result, it is suggested that the INVR can provide a scientific base for measuring the symptoms of nausea, vomiting, and retching for nurses to improve patients' care and quality of life.