2P-173 Nano carbon material reinforced non-woven carbon fiber based film for enhanced electromagnetic shielding effectiveness

양기훈,채규윤,한지훈,국선 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

A series of graphene-oxide (GO) coated non-woven carbon fabric was developed, and their thermal stability, tesnsile strength and electromagnetic interference shielding performance was investicated. GO was obtaibned by oxidation of graphite nano flakes, and it was confirmed with XPS and Raman spectroscophy. In the coateing process, GO and polyvinylidene fluoride in N,N-dimethylformamide solution were used. After coating, PVDF filling the space between carbon fiber and GO coated into carbon fiver matrix was observed. Thermal stability and tensile strength was increased to around 450ºC and 100kgf/㎠ respectively. EMI shielding effectiveness was maximum 55dB at 2700MHz.

1P-171 Developing a high-efficiency electromagnetic interference shielding and heat emitting composite material using carbon fibers and carbon-nano materials

양기훈,자야산타,국선,채규윤 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.0

공기 유속과 저항체 형태에 따른 압력계수 측정에 관한 풍동 실험

양기훈,최준섭,정동양 한국기술교육학회 2006 한국기술교육학회지 Vol.6 No.2

In the wind tunnel circular cylinder and airfoil models were provided in order to measure the relative head differences at the various air-flow velocity.The results of this study were as follows:⑴ The pressure coefficients of circular cylinder model were shown qualitatively similar distribution, not influenced greatly by air-flow velocity in the fluid-flow field. ⑵ When angle of attack α is 0°, the pressure coefficients of the airfoil model were not shown large difference at the air-flow velocity, but in general, they were increased as the air-flow velocity was increased. In addition, the pressure coefficients were shown qualitatively similar distribution in all velocities. ⑶ The airfoil model has had smaller change in pressure coefficient than the circular cylinder model. ⑷ The pressure coefficient of the airfoil model based on the angle of attack α has had remarkable difference in increase and decrease as X/C has been getting smaller.

모바일 촉각 디스플레이 기술동향

양기훈 제어로봇시스템학회 2014 제어로봇시스템학회지 Vol.20 No.3

본 기술 동향에서는 햅틱 기술과 관련된 최근의 동향에 대해서 살펴보기로 한다. 특히 진동 촉각을 기반으로 한 모바일 기기용 햅틱스는 관련 연구들이 활발하에 진행 중이며 이 중에 몇 가지 연구들과 활용되는 액추에이터 등에 대한 연구들을 바탕으로 앞으로의 촉각 기반 생태계를 예측해 보고, 아울러 의료, 휴대폰, 컴퓨터, 재활 분야등에서 필요로 하고 또 활용 가치가 있는 햅틱 기술들에 대해서 고찰해 보기로 한다. 최근에 각광받는 웨어러블 기기등도 내부에 다양한 센서와 액추에이터를 내장하려는 움직임이 있고, 휴대폰 등에서 진동 액추에이터를 활용하여 소리를 대체하듯 촉각 기술이 터치 스크린 기반 시장을 한 단계 발전시켜 차세대 입력 장치로 발전할 수 있는 가능성을 가늠해 볼 수 있을 것이다. 지속적인 연구를 통해 관련 분야에서 필요한 촉각 기술을 개방한다면 햅틱 연구자들이 그토록 염원하는 촉각 기반 시장의 확대 성장도 그리 오랜 시일이 걸리지 않을 것으로 기대한다.

정상 어린이에서 혈청 인슐린양 성장인자-I과 인슐린양 성장인자 결합단백-2 및 -3의 농도 분석

양기훈 대한소아청소년과학회 2005 Clinical and Experimental Pediatrics (CEP) Vol.48 No.3

Purpose:We performed this study to evaluate the mean serum levels of insulin-like growth factor (IGF)-I, insulin-like growth factor binding protein(IGFBP)-2 and IGFBP-3 in healthy Korean children according to age and sex. Methods:Ninety two healthy children, consisting of 42 boys and 50 girls, were classified into five groups according to age:neonate; infancy; early childhood; late childhood; and adolescence. We measured serum levels of IGF-I, IGFBP-2 and IGFBP-3 by enzyme-linked immunosorbent assay(ELISA) and analysed the serum levels according to sex and age group. Results:For boys, the mean serum levels of IGF-I(ng/mL) in neonate, infancy, early childhood, late childhood and adolescence were 41.1±3.6, 70.9±33.7, 103.5±97.2, 89.8±46.5 and 51.4±27.8, respectively. Those of IGFBP-2(ng/mL) were 8.2±3.4, 5.8±0.4, 9.3±4.0, 9.5±1.1 and 7.0±0.5, respectively. Those of IGFBP-3(ng/mL) were 559.2±215.2, 1,333.3±692.5, 2,254.6±1,513.8, 2,447.1±1,464.2, 1,533.6±807.4, respectively. For girls, the mean serum levels of IGF-I(ng/mL) according to five age groups were 53.3±9.5, 99.3±45.8, 69.6±51.1, 106.2±67.0 and 145.1±127.8, respectively. Those of IGFBP-2 (ng/mL) were 9.1±7.4, 5.3±0.9, 6.9±2.0, 10.5±3.0 and 7.9±1.3, respectively. Those of IGFBP-3(ng/ mL) were 858.2±433.4, 1,834.8±851.3, 1,404.3±570.2, 2,203.5±899.4 and 2,029.3±1,316.7, respectively. There were significant positive correlations observed between IGF-I and IGFBP-3 levels(r=0.589, P= 0.000). Conclusion:IGF-I and IGFBP-3 levels increased as children get older. The peak level of IGFBP-3 was observed in late childhood for both boys and girls, suggesting a current trend of children reaching peak growth velocity before adolescence. The IGFBP-2 level was higher in neonates compare to infancy, suggesting that IGFBP-2 is an important substance for fetal growth. 목 적 : 혈청 IGF-I, IGFBP-2, IGFBP-3 농도 및 IGF-I/ IGFBP-3 molar ratio는 소아의 성장 발달, 당뇨병, 비만 및 악성종양의 진단, 예후 예측과 치료후 추적에 유용한 지표이지만 성별, 연령별, 인종별 변이가 있다. 저자들은 우리나라 어린이의 성별 및 연령군별 혈청 IGF-I, IGFBP-2, IGFBP-3 농도 및 IGF-I/IGFBP-3 molar ratio의 정상 표준치 확립을 위하여 본 연구를 시행하였다.방 법 : 총 92명(남자 42명, 여자 50명)의 건강한 어린이를 대상으로 하였고, 신생아군 9명(남자 3명, 여자 6명), 영아군 19명(남자 9명, 여자 10명), 유아군 24명(남자 13명, 여자 11명), 학령군 30명(남자 12명, 여자 18명), 청소년군 10명(남자 5명, 여자 5명)으로 분류 후, ELISA 방법을 이용하여 혈청 IGF-I, IGFBP-2 및 IGFBP-3 농도를 측정하였고, 각 군간의 IGF-I, IGFBP-2, IGFBP-3 및 IGF-I/IGFBP-3 molar ratio를 비교분석하였다.

Multiple Energy Harvesting for Highly Efficient Wireless Power Receiver

양기훈,김영훈,나형준,김호원,오태섭,김재빈,조종완,이강윤 한국과학기술원 반도체설계교육센터 2022 IDEC Journal of Integrated Circuits and Systems Vol.8 No.1

This paper shows an efficient wireless power receiver (WPR) based on multiple energy harvesting (EH) methodology. The proposed WPR structure consists of a high and low power route holding power conversion efficiency (PCE) high in a broad scope input. Solar/Thermoelectric/ Triboelectric/Vibration/RF energies are proposed as multiple hybrid energy sources. Thermal and solar energy harvester is proposed with Maximum Power Point Tracking (MPPT) in time-domain. For triboelectric/vibration EH and high-power path energy harvesting, highly efficient rectifier in full wave (FWR) and RF-DC converter operating at 5.8 GHz are presented to increase the input power range. A 0.18 µm Bipolar-CMOS-DMOS process is used for the chip fabrication. The RF-DC operating at 5.8 GHz attains 76.9% PCE at 30 dBm input. A PCE of 69.85% is achieved using the harvester of solar energy as a peak point. The RF-DC converters of low power path in 900 MHz and 2.4 GHz frequency attain 73% and 71.9% PCE results at 0 dBm in 1 mW as a peak.

제조 공정을 위한 산업용 로봇의 원격 제어 시스템

양기훈,류석우,류영선 제어로봇시스템학회 2014 제어로봇시스템학회 국내학술대회 논문집 Vol.2014 No.5

Utilizing Carbon Nano materials for higher Electromagnetic shilding effectiveness

양기훈,라굴란,국선,정하수,채규윤 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

With the improvement of electronic technology, it has been significantly important to protect electric curcuits from unwanted external electromagnetic distracntions. Electromagnetic interference can cause physical damage, modulated data and higher error rate. In this study, nonwoven carbon fabric coated with Graphene was developed using a very simple method. Oxidation state and coating morphology of graphite nano plate was confirmed with XPS analysis, Raman spectroscopy and SEM. Maximum electromagnetic interference shielding effectiveness of graphene coated nonwoven carbon fabric is 41.14dB.

공급사슬 적응성의 선행 및 후행 요인과 매개효과에 관한 연구

양기훈,이성현,허대식,민순홍 한국로지스틱스학회 2024 로지스틱스연구 Vol.32 No.1

To maintain a competitive advantage in supply chain management, companies require the capability of adapting to major changes occurring in supply chains, which involves recognizing market changes and the ability to adapt to them. Despite the emphasis on the importance of supply chain adaptability in real corporate cases and prior research, there is a relative shortage of studies on the antecedents and effects of supply chain adaptability. Therefore, this study proposes and tests a theory of supply chain adaptability based on the Strategy-Positional Advantage-Performance framework (SPP framework) and the concept of dynamic capabilities. Specifically, an organizational learning culture is proposed as an antecedent of supply chain adaptability, and the mediating effect of supply chain adaptability in the relationship between organizational learning culture and firm performance is examined. The empirical test was performed using survey responses from 209 manufacturing companies in 15 countries, including North America, Europe, and Asia. This study is significant in that it (1) conceptualized and empirically confirmed that supply chain adaptability is a multidimensional construct, (2) recognized that organizational learning culture can function as an antecedent of supply chain adaptability, and (3) theorized and confirmed that supply chain adaptability mediates the organizational learning culture and firm performance based on the SPP framework.

능력중심사회 구현을 위한 NCS의 역할

양기훈 대한경영학회 2016 대한경영학회 학술발표대회 발표논문집 Vol.2016 No.1

현 정부에서는 학벌이 아닌 능력중심사회의 구현을 위해 국가직무능력표준(NCS)을 기반으로 한 교육훈련, 자격 등의 개편을 추진 중에 있으며, 능력중심 기업문화 조성을 위하여 NCS 기반의 채용, 인력관리 등의 확산을 유도하고 있다. 이에 본 연구에서는 NCS의 개발 및 활용에 관한 개념과 정부의 능력중심사회 구현을 위한 세부 국정과제 추진 현황을 소개하고자 하며, 세부 영역별로 몇 가지 정책적 제언을 하고자 한다. 이러한 최근의 움직임이 정부의 정책으로 끝나지 않기 위해서는 다양한 이해관계자의 참여와 국민의 공감대 형성이 함께 하여야 할 것이다.