• Transactions on Electrical and Electronic Materials
• /
• 제15권3호
• /
• pp.149-154
• /
• 2014

A new CMOS analog design methodology using an independently optimized self-cascode (SC) is proposed. This idea is based on the concept of the dual-workfunction-gate MOSFETs, which are equivalent to SC structures. The channel length of the source-side MOSFET is optimized, to give higher transconductance ($g_m$) and output resistance ($r_{out}$). The highest $g_m$ and $r_{out}$ of the SC structures are obtained by independently optimizing the channel length ratio of the SC MOSFETs, which is a critical design parameter. An operational amplifier (OPAMP) with the proposed design methodology using a standard digital $0.18-{\mu}m$ CMOS technology was designed and fabricated, to provide better performance. Independently $g_m$ and $r_{out}$ optimized SC MOSFETs were used in the differential input and output stages, respectively. The measured DC gain of the fabricated OPAMP with the proposed design methodology was approximately 18 dB higher, than that of the conventional OPAMP.

• 공학교육연구
• /
• 제14권1호
• /
• pp.64-73
• /
• 2011

본 연구는 공학설계 교육을 통해 진행되는 개념설계와 제품설계의 문제해결과정이 학생들의 자기주도학습 능력 향상에 어떠한 영향을 미치는지 구명하는데 목적이 있다. 이를 위해 입문설계교육을 수강한 학생들을 대상으로 심층면담을 실시하였는데, 이를 통해 도출된 주요 연구결과는 다음과 같다. 첫째, 문제해결과정을 통해 학습욕구를 진단하고 해결해야 할 문제를 정의하는 것의 중요함을 깨닫게 되었다. 둘째, 문제정의 후 문제해결을 위한 학습계획을 구성하고 이를 체계적으로 수행해 나가는 것이 중요함을 인지하게 되었다. 셋째, 문제해결을 진행하는 과정에서 지속적인 수정 보완이 필요함을 알게 되었고, 과정 종료 후에도 평가 및 점검이 필요하다는 사실을 인지하게 되었다. 이러한 결과를 토대로 볼 때 설계 교육의 문제해결과정은 학생들이 자기주도적으로 학습하는데 긍정적인 영향을 미치고 있음을 알 수 있었다.

• 대한건축학회논문집:구조계
• /
• 제35권9호
• /
• pp.199-206
• /
• 2019

Experimental study on the durability characteristics to examine the feasibility of concrete with high water-tightness and self-healing performance to minimize maintenance of concrete for artificial ground is as follows. 1) When blending agent, swelling agents, and curing accelerator were added on the ternary system cement with blast-furnace slag fine particles and fly ash to give a self-healing property, higher blending strengths by 82% at design standard strength of 24MPa and by 74% at design strength of 30MPa, respectively could be obtained. 2) The permeability test for the specimens having high water-tightness and no shrinkage showed that the permeability was reduced at maximum of 98%. However, the permeability was decreased as the design strength was increased, showing the reduction rate of 87% at the design strength of 50MPa. 3) The depth of carbonation of blast-furnace slag and fly ash was increased in all the specimens compared with those of OPC only. However, as the material age was increased, carbonation penetration depth was decreased compared with the reference blend. 4) Compared with the reference blending using only OPC, the freeze-thaw resistance was higher in the case of blending with 40% of blast-furnace slag and 10% of fly ash at the design standard strength of 50MPa. In addition, the freeze-thaw resistance in general was superior in the design standard strength of 50MPa with the lower water-binder ratio (W/B) as compared with the design standard strength of 24MPa and 30MPa with the high water-binder ratios.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
• /
• pp.2931-2934
• /
• 2003

This paper has been studied the electronic ballast by the self-oscillated inverter. The self-oscillated ballast can reduce the stress of the switch of the inverter. But the self-oscillating method is not easy to analyze and design. There arc three kinds of cores for the oscillating transformer： Ring core, EI-core, and Drum core. In this paper, we are studied the characteristics of three kinds of cores in using electronic ballast by the self-oscillated inverter.

• 보건의료산업학회지
• /
• 제7권4호
• /
• pp.119-129
• /
• 2013

The purpose of this study was to identify factors influencing professional self-concept among nursing students. A descriptive survey design was used with convenience sample of 250 nursing students studying in 1 nursing college. The data were obtained from November 17 to 30, 2012 by self-reported questionnaire. The collected date were analyzed using SPSS WIN 18.0 program. The mean score for professional self-concept, self-esteem and, self-efficacy were at the intermediate level, with the value of 3.27, 3.14 and 3.78. There were moderate positive correlation between the professional self-concept and self-esteem(r=0.580, p<.001), the professional self-concept and self-efficacy (r=0.645, p<.001) and there were moderate positive correlation between self-esteem and self-efficacy(r=0.611, p<.001). The influencing factors in professional self-concept of nursing students were self esteem, self efficacy, and motivation of nursing(Adj $R^2=.479$). In order to encourage nursing college students professional self-concept, the nursing college should make efforts to develop a curriculum and program for improving self-esteem and self-efficacy.

• 한국주거학회논문집
• /
• 제23권1호
• /
• pp.97-105
• /
• 2012

The purpose of this study is to find the characteristics of design council criteria of metropolitan cities in Koreas. For comparative analysis, four main concepts are used ; 1) self-administering vs discretionary 2) prescriptive vs performance 3) conformity vs contrast 4) point system of criteria. The results of this study were as follows; 1) there were three types of cirteria; strong discretionary (DG), discretionary oriented (BS, US) and combination type (SL, DJ, ICN, GJ) 2) structural properties of forms are controlled by prescriptive criteria, and layout or design elements by performance criteria 3) visual openness and diversity are main items of most metropolitan cities 4) street-faced design was neglected but tended to focus on the self-contained layout 5) visual density indexes were diversified from elevation blockage degree. For further advanced research, it is necessary to investigate the actual effects and differences of regulative types - prescriptive vs performance, and of each design criteria, especially prescriptive ones in improving the design quality.

• 한국화예디자인학연구
• /
• 제45호
• /
• pp.47-56
• /
• 2021

본 연구는 꽃 디자인 능력을 향상시키기 위한 효과적인 교수법을 연구하기 위해 사전 학습(e- 러닝), 매뉴얼로 모델링, 학습자의 실습, 1:1 교육 코칭, 자기 평가, 코칭 행동 평가(1차, 2차) 등의 모델을 작성하여 적용되었다. 첫째, 사전 학습을 통한 인지 실습 교육은 꽃 디자인 실천에서 매우 필수적이다. 둘째, 플로랄 디자인의 연습 수업은 교수가 일반적으로 예제를 설정하고 학습자가 따라하는 수업이다. 셋째, 본 연구는 체크리스트를 작성하고, 자체 평가를 통해 반영하고, 완성된 작품에 대한 꽃무늬 디자인의 요소, 원리 및 기술 부분에 따라 평가 양식을 작성하는 것이다. 그 이후로 각 교수의 평가 양식을 교수가 직접 분석하여 피드백을 제공한 결과 자체 작업의 자체 검토 및 기술 부품의 품질 수준이 향상되었다. 넷째, 수업 시간 내에 완료 한 기존 수업과는 달리, 연습 수업은 자발적 연습을 했다. 다섯째, 마지막 단계에서 포트폴리오의 작업 프로세스를 배치하여 다시 스케치 및 촬영을 통해 학습자가 만든 작품을 평가하는 것이다. 또한 체크리스트와 함께 제작 방법 및 주의 사항을 준비하고 교수님의 피드백을 받으면서 꽃 디자인 능력이 크게 향상되었다. 결론적으로, 이 연구는 학습자에 의한 연습 형태의 여섯 단계를 통한 꽃 디자인의 기본 능력을 향상시키는 데 훌륭한 학습 모델이 된다는 것을 발견했다. 따라서 학습자의 자기 주도적 학습에 큰 도움이 될 것이므로 향후 이와 관련된 교재 개발 및 현장 적응이 고려된다.

• 한국전자파학회논문지
• /
• 제20권2호
• /
• pp.208-214
• /
• 2009

UWB USPR 시스템 응용 초광대역 마이크로스트립-CPS(Coplanar Stripline) 발룬을 이용한 self-complementary 스파이럴 안테나의 설계와 실험적 결과를 제시하였다. 초광대역 특성을 갖는 평면형 마이크로스트립-CPS 발룬을 적용하여 스파이럴 안테나 고유의 초광대역 특성을 유지하게 하였고, 각각 설계된 안테나와 발룬을 임피던스 정합의 방법을 이용하여 연결함으로 간단한 안테나 설계 과정을 보였다. 설계된 스파이럴 안테나는 등각 형태의 self-complementary 스파이럴 안테나이다. 제작된 안테나는 2.9 GHz에서 12 GHz의 넓은 주파수 특성을 가지며, 2.7에서 5.3 dB의 비교적 평탄한 이득과 $70^{\circ}$ 이상의 빔 폭을 가졌다. 이 결과를 통해 초광대역 마이크로스트립-CPS 발룬의 스파이럴 안테나의 적용 가능성을 검증하였다.

• 한국의상디자인학회지
• /
• 제21권4호
• /
• pp.1-16
• /
• 2019

This study proposes the requirements for students in colleges majoring in fashion at two-year colleges in Seoul and Gyeonggi-do to perform behaviors in preparation for a further career more effectively by identifying the impact of social support on the career decision-making self-efficacy, and behaviors preparing a further career. The results of this study are described below. In accordance with the analysis on the relationship between career decision-making self-efficacy and behaviors preparing a further career, and the social support, the social support had a positive impact on the career decision-making self-efficacy and a negative impact on the behaviors preparing a further career. Moreover, the career decision-making self-efficacy had a positive impact on the behaviors preparing a further career. In accordance with the analysis, social support from family members or relevant third parties is required for improving the behavior of students majoring fashion in colleges to prepare a further career. To this end, the quantity or scope of social support is not the main issue, but the meticulous approach to fit each student's need for making students recognize such social support. It is important for students in colleges to enhance career decision-making self-efficacy by accurately identifying their abilities, values or desires.

• Child Health Nursing Research
• /
• 제14권3호
• /
• pp.269-276
• /
• 2008

Purpose: In this study the effects of Self-Development program on self-esteem and communication in middle school students were examined. Method: Forty-three middle school students in D City participated in a survey, which was carried out from October to November, 2007. To test the effects of the Self-Development Program, the students were divided into two groups, an experimental group (23) and a control group (20). The research design used in this study was a nonequivalent control group pre-posttest quasi-experimental research design. The research tools included a self-esteem scale and a communication scale. Chi-square test, paired t-test, and t-test were used to analyze the data with the SPSS/WIN 12.0 program. Result: Significant differences were found in self-esteem scores between the experimental group and the control group. But there were no significant differences between the two groups on communication scores. Conclusion: The results suggest that the Self-Development program is a useful nursing intervention for improving the self-esteem of middle school students.