노년 청각손상자와 청각장애의 삶의 질 관련성 연구

劉俊榮,張勝成 대구대학교 특수교육재활과학연구소 2006 再活科學硏究 Vol.24 No.2

The hearing impairment happened extensively in the elderly and often resulted in the hearing handicap. A lot of study confused the hearing impairment with the hearing handicap and replaced the score of quality of life by the hearing handicap score to calculate the quality adjusted life years and analyzed the cost-utility of aural rehabilitation. In this study, the confusion of hearing impairment and hearing handicap was clarified, and the relevance between hearing handicap and quality of life was explored in order to examine the fitness of replacing the score of quality of life by the hearing handicap score. The result of this study indicated that the correlation between the hearing handicap and the quality of life. The fitness of correlating model of the hearing handicap and the quality of life was not accepted. So, it was not suggested that replacing the score of quality of life by the hearing handicap score. The inventory of disease-specific quality of life should be developed. Secondly, the poor fitness of correlating model of the hearing handicap and the quality of life could be resulted from the other variables that shall be included in the model. It was proposed to include relevant variables into the model in the future. 청각손상은 노년기에 광범위하게 발생하는 문제이다. 심각한 청각장애를 자주 일으킨다. 많은 연구는 청각손상과 청각장애를 혼돈하는 것 뿐 만아니라 자주 청각장애 검목표의 득점으로 피실험자의 생활 품질을 대표한다. 심지어 청각장애 검목표의 득점으로 생활 품질 조정년을 계산한다. 이것으로 청각 재활의 성공 효과를 분석한다. 본 연구는 청각 손상과 청각장애의 다른 점을 밝히는 것 외에도 주요 목적은 청각장애와 생활 품질의 관련성을 이해하고자 하는 것이다. 이것으로 청각장애 검목표를 생활 품질을 삼는 정당성을 관찰한다. 연구결과에 나타나는 것은 청각 표현과 생활품질의 관련성은 높지 않은 결과를 얻었다. 이 두 가지의 관련 양식은 일반화 하기는 제한점을 갖는다. 그래서 이론적 개념에서 청각 표현과 생활품질은 각자 다른 내용을 갖추고 있다. 자료 통계의 분석 결과도 이 두 가지의 관련 양식에 대해서 유의한 결과를 얻지 못했다. 그래서 청각표현 능력으로 피실험자의 생활 품질을 대신할 수 없다. 마땅히 청각 손상자에게 맞는 적합한 생활 품질 설문지를 발행해야한다. 그 다음에 두 가지의 관련 양식의 관련도 적다. 아마도 청각 손상자의 청각 표현과 생활 품질 간에는 많은 변인의 영향이 존재하기 때문이다. 미래의 연구는 더 많은 상관 관련 인소를 귀납해서 이 이론구조를 검증해야한다는 것을 건의한다.

Mathematical Thinking through Different Representations and Analogy

( Cheng Chun Chor Litwin ) 한국수학교육학회 2011 수학교육연구 Vol.15 No.1

Mathematical thinking is a core element in mathematics education and classroom learning. This paper wish to investigate how primary four (grade 4) students develop their mathematical thinking through working on tasks in multiplication where greatest products of multiplication are required. The tasks include the format of many digit times one digit, 2 digits times 2 digits up to 3 digits times 3 digits. It is found that the process of mathematical thinking of students depends on their own representation in obtaining the product. And the solution is obtained through a pattern/analogy and "pattern plus analogy" process. This specific learning process provides data for understanding structure and mapping in problem solving. The result shows that analogy allows successful extension of solution structure in the tasks.

A Novel Single-Stage LED Driver with Coupled Inductors and Interleaved PFC

Chun-An Cheng,Chien-Hsuan Chang,Hung-Liang Cheng,Ching-Hsien Tseng 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

This paper proposes a novel single-stage lightemitting diode (LED) driver with coupled inductors and interleaved power-factor correction (PFC), suitable for streetlight applications. The presented LED driver integrates an interleaved boost PFC converter with coupled inductors and a half-bridge-type series-resonant converter cascaded with a full-bridge rectifier into a single-stage power-conversion circuit. Coupled inductors inside the interleaved boost PFC converter sub-circuit are designed to operate in discontinuous-conduction mode (DCM) for achieving input-current shaping, and the half-bridge-type series-resonant converter cascaded with a full-bridge rectifier is designed for obtaining zero-voltage switching (ZVS) on two power switches to reduce their switching losses. Analysis of operational modes and design equations for the presented LED driver are described and included. In addition, the proposed driver features high power factor, low total-harmonic distortion (THD) of input current and soft-switching. Finally, a prototype 165W-rated LED driver is developed and tested with a utility-line input voltage of 110V. Satisfactory outcomes from experimental results demonstrate the feasibility of the proposed circuit.

Teaching of Division of Fractions through Mathematical Thinking

( Cheng Chun Chor Litwin ) 한국수학교육학회 2013 수학교육 학술지 Vol.2013 No.1

Division of fractions is always a difficult topic for primary school students. Most of the presentations in teaching the topic in textbooks are procedural, asking students to invert the second fraction and multiply it with the first one, that is, (a/b)÷(c/d)=(a/b)×(d/c) Such procedural approach in teaching diminishes both the understanding of structure in mathematics and the interest in learning the subject. This paper discussed the formulation of teaching the division of fractions, which based on research lessons in some primary five classrooms. The formulated lessons started with an analogy to division of integers and working with division of fractions with equal denominators and then extended to division of fractions in general. It is found that the using of analogy helps students to invent their procedure in working the division problem. Some procedures found by students are discussed, with the focus on the development of their invention and mathematical thinking.

A Novel Single-Stage High-Power-Factor Electronic Ballast for High-Pressure Sodium (HPS) Lamps in Streetlight Applications

Chun-An Cheng,Wei-Shiang Hung 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

This paper proposes a novel single-stage highpower-factor electronic ballast for high-pressure sodium (HPS) lamps suitable for streetlight applications; this ballast integrates an interleaved buck-boost converter with coupled inductors and a full-bridge inverter for supplying low-frequency square-wave sources to the HPS lamp without incurring acoustic resonance. A 250W-rated prototype HPS lamp ballast circuit operating with 110V-rms input utility-line voltage has been successfully implemented and tested. The functionalities of the presented ballast are demonstrated through satisfactory experimental results in terms of high power factor (>0.99), low utility-line current total harmonic distortion (<3%), and high circuit efficiency (>89%).

Teaching of Division of Fractions through Mathematical Thinking

Chun Chor Cheng 한국수학교육학회 2013 수학교육연구 Vol.17 No.1

Division of fractions is always a difficult topic for primary school students. Most of the presentations in teaching the topic in textbooks are procedural, asking students to invert the second fraction and multiply it with the first one, that is, Such procedural approach in teaching diminishes both the understanding of strcture in mathematics and the interest in learning the subject. This paper dicussed the formulation of teaching the division of fractions, which based on research lessons in some primary five classrooms. The formulated lessons stared with an analogy to divesion of integers and working with division of fractions with equal denominators and then extended to division of fractions in general. It is found that the using of analogy helps students to invent their procedure in working the division problem . Some procedures found by students are discussed, with the focus on the development of their invention and mathematical thinking.

A Novel Single-Stage Cost-Effective Electronic Ballast for HID Lamps with High Power Factor

Chun-An Cheng,Chen-Wei Ku 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

High-intensity-discharge (HID) lamps are widely utilized in a variety of lighting circumstances that need high luminance. This paper proposes a single-stage electronic ballast for HID lamps; the ballast offers power factor correction and is acoustic-resonance-free. The presented HID lamp ballast integrates a discontinuous-conduction-mode (DCM) operated bridgeless power factor correction (PFC) converter for shaping the input utility-line current with a high/low-frequency square-wave-driven half-bridge inverter for supplying low-frequency square-wave sources to the HID lamp. The features of the proposed ballast are high power factor, low total harmonic distortion (THD) of the input current, cost-effectiveness, and that it is free of acoustic resonance. This paper analyzes the operational modes, key design guidelines and experimental results of the proposed ballast for a 70W HID lamp operating with 110V-rms input utility-line voltage.

Study of PD Location in Generators by PD Pulses Propagation

Cheng, Yang-Chun,Li, Cheng-Rong,Wang, Wei The Korean Institute of Electrical and Electronic 2006 Transactions on Electrical and Electronic Material Vol.7 No.5

When a partial discharge takes place at the stator of a generator, the electrical pulse will propagate along the stator bars and the capacitor chains formed by the end part of the stator winds. On the first path, the pulse propagates as a travel wave at slow speed. On the second path, the pulse propagates at quick speed. Based on the data of the experiments on a real 50 MW steam generator, the author has found the pulses can propagate by magnetic field of the stator winding. It was studied that how to locating the partial discharge by signals coming from the different paths, including the features of signals on the two paths at time domain and frequency domain, the measurement frequency rang of the signals, the blind area, the advantage and disadvantage of this method.

An Extended Multi-Server-Based User Authentication and Key Agreement Scheme with User Anonymity

( Chun-ta Li ),( Cheng-chi Lee ),( Chi-yao Weng ),( Chun-i Fan ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.1

With the explosive growth of computer networks, many remote service providing servers and multi-server network architecture are provided and it is extremely inconvenient for users to remember numerous different identities and passwords. Therefore, it is important to provide a mechanism for a remote user to use single identity and password to access multi-server network architecture without repetitive registration and various multi-server authentication schemes have been proposed in recent years. Recently, Tsaur et al. proposed an efficient and secure smart card based user authentication and key agreement scheme for multi-server environments. They claimed that their scheme satisfies all of the requirements needed for achieving secure password authentication in multi-server environments and gives the formal proof on the execution of the proposed authenticated key agreement scheme. However, we find that Tsaur et al.`s scheme is still vulnerable to impersonation attack and many logged-in users` attack. We propose an extended scheme that not only removes the aforementioned weaknesses on their scheme but also achieves user anonymity for hiding login user`s real identity. Compared with other previous related schemes, our proposed scheme keeps the efficiency and security and is more suitable for the practical applications.

A Single-Stage LED Tube Lamp Driver with Input-Current Shaping for Energy-Efficient Indoor Lighting Applications

Chun-An Cheng,Chien-Hsuan Chang,Hung-Liang Cheng,Tsung-Yuan Chung,Ching-Hsien Tseng,Kuo-Ching Tseng 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

This study proposes a single-stage light-emitting diode (LED) tube lamp driver with input-current shaping for T8/T10-type fluorescent lamp replacements. The proposed AC–DC LED driver integrates a dual-boost converter with coupled inductors and a half-bridge series-resonant converter with a bridge rectifier into a single-stage power conversion topology. This paper presents the operational principles and design considerations for one T8-type 18 W-rated LED tube lamp with line input voltages ranging from 100 V rms to 120 V rms. Experimental results for the prototype driver show that the highest power factor (PF = 0.988), lowest input current total harmonic distortion (THD = 7.22%), and highest circuit efficiency (η = 92.42%) are obtained at an input voltage of 120 V. Hence, the proposed driver is feasible for use in energy-efficient indoor lighting applications.