선인장 양심실 보조장치의 설계 및 임상적용을 위한 평가

민병구,박찬영,최재순,이혁수,황창모,김삼성,윤걸중,김종원,선경,이경갑,정종태,김원곤 제주대학교 인공심장이식연구소 2001 인공심장 연구 Vol.2 No.1

현재 개발되고 있는 맥동형 이식형 인공심장은 완전이식형 인공심장과 좌심실보조장치 뿐이다. 좌심실보조장치를 장착한 환자의 10~15%가 우심실의 보조를 필요로하고 완전이식형 인공심장의 장착을 위해서는 자연심장을 제거해야하는 상황에서 이식형 양심실보조장치에 대한 필요성이 대두되고 있다. 본 연구진은 완전이식형 인공심장으로 개발된 한국형 인공심장을 개선하여 양심 실 보조장치를 개발하였다. 양심실보조장치는 이동형 작동기식 미케니즘을 이용하고 있으며 에너지 변환장치와 감속기로 구성된 작동기와 혈액주머니, 그리고 내장형 제어기로 구성되어 있다. 선인장 펌프로 명명된 KAH350은 캐뉼라의 연결을 위한 커넥터를 포함하여 길이 177mm, 폭 164mm, 높이 67 이고 무게 780g이며 최대 심박출량은 5L/min 이다. 양심실보조장치로 개발된 선인장펌프는 좌심실보조장치로도 응용이 가능하다. 이식적합성과 생체적합성을 평가하기 위하여 좌심실보조장치로 5회, 양싱실보조장치로 6회의 동물실험을 수행하였다. 각각 최장 28일간 생존하였으며 11회의 동물실험중 장치의 결함에 의한 것이 3회 있었는데 이들은 모두 전자장치의 결함과 방수처리문제였다. 현재 이식적합성과 일박출량을 향상시킨 KAH400모델이 개발중이다. The types of pulsatile implantable artificial hearts that are on the way of development and have been developed are totally implantable artificial heart and implantable left ventricular assist device (LVAD). Approximately 10% to 15% of all patients Implanted with wearable VADs have required right heart support with another device. And it is reluctant to patient who should remove his or her own heart to be implanted with total artificial heart. These situations drive the development of implantable bi-ventricular assist device (BVAD). The Korean BVAD was develophed by modifying the moving actuator type Korean artificial heart. This electro-mechanical BVAD comprises actuator including energy converter and reduction gear train, blood sacs, and internal motor and energy controllers. The KAH350 which is named as 'Cactus Pump' is 177mm in length, 164mm in width, and 67mm in thickness including connectors and nuts. The weight and maximum cardiac output of Cactus Pump is 780g and 5L/min, respectively. The Cactus Pump that was developed as BVAD could be used as LVAD by attaching compliance caps on the 2 ports of one ventricle. The animal experiments were undergone 5 times for LVAD, and 6 times for BVAD. The best records were 28 days survival in both applications. There were 3 times of device failure and they were all associated with electrical connection and hermetic sealing. The KAH400 that has improved anatomical fitting characterisitcs and stroke volume is on development.

A Study on Strategies of Multinational Bakery Retailers in China : Focused on Paris Baguette and Competitors

Byoung-Goo KIM,Hee-Joong Hwang 한국유통과학회 2020 유통과학연구 Vol.18 No.12

Purpose: For bakery retailers that want to enter the Chinese market, this study seeks to draw implications through the analysis of Paris Baguette, Paul Bakery and local competitors. In particular, the study analyzes entry strategies, as well as the advantages and disadvantages of the companies. Research design, data and methodology: This study analyzed the Chinese bakery industry and overviewed the policy of bakery industry. The research method utilized Chinese Statistical Yearbook of Food Industry and literature related to Chinese bakery industry. Additionally, this study used case analysis methods for foreign and local bakery enterprises in the bakery industry. Results: During the rapid growth of bakery industry, Paris Baguette made a successful settlement by utilizing localization strategy; while on the contrary, Paul Bakery took a standardization strategy and failed in the Chinese market. Conclusions: Paris Baguette succeeded in launching localized products after thoroughly analyzing products that suit local tastes in China. However, Paul Bakery has been knocked out of the Chinese market for failing to capture the taste of the Chinese people by launching standardized products that reproduce French culture and taste. As such, the Chinese market is huge and differences exist in different provinces, so standardization and localization strategies should be appropriately utilized.

Use of Artificial Intelligence-Based Software as Medical Devices for Chest Radiography: A Position Paper from the Korean Society of Thoracic Radiology

Hwang Eui Jin,Goo Jin Mo,Yoon Soon Ho,Beck Kyongmin Sarah,Seo Joon Beom,Choi Byoung Wook,Chung Myung Jin,Park Chang Min,Jin Kwang Nam,Lee Sang Min 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.11

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Issues with the electrical characterization of graphene devices

Byoung-Hun Lee,Young-Gon Lee,Uk-Jin Jung,Yong-Hun Kim,Hyeon-Jun Hwang,Jin-Ju Kim,Chang-Goo Kang 한국탄소학회 2012 Carbon Letters Vol.13 No.1

Graphene is an attractive material for device applications, but device characteristics are very unstable because the graphene is very sensitive to environmental factors such as charges nearby the graphene, metal contacts, defects, contaminants and other adsorbates. Since the interactions between graphene and environmental factors affect the electrical characteristics of graphene devices, the interpretation of electrical characteristics as simple as current-voltage curves is non-trivial, despite the common practice of using well known electrical characterization methods that have been used in silicon MOSFET. This paper addresses major obstacles in the electrical characterization of graphene devices and offers countermeasures to improve the accuracy of electrical characterization methods.

Enhanced Current Drivability of CVD Graphene Interconnect in Oxygen-Deficient Environment

Chang Goo Kang,Sang Kyung Lee,Young Gon Lee,Hyeon Jun Hwang,Chunhum Cho,Sung Kwan Lim,Jinseong Heo,Hyun-Jong Chung,Heejun Yang,Sunae Seo,Byoung Hun Lee IEEE 2011 IEEE electron device letters Vol.32 No.11

<P>Graphene has been considered as a candidate for interconnect metal due to its high carrier mobility and current drivability. In this letter, the breakdown mechanism of single-layer chemical-vapor-deposited (CVD) graphene and triple-layer CVD graphene has been investigated at three different conditions (air exposed, vacuum, and dielectric capped) to identify a failure mechanism. In vacuum, both single- and triple-layer graphenes demonstrated a breakdown current density as high as ~10<SUP>8</SUP> A/cm<SUP>2</SUP>, which is similar to that of exfoliated graphene. On the other hand, the breakdown current of graphene exposed to air was degraded by one order of magnitude from that of graphene tested in vacuum. Thus, oxidation initiated at the defect sites of CVD graphene was suggested as a major failure mechanism in air, while Joule heating was more dominant with dielectric capping and in vacuum.</P>

ECC 암호시스템을 활용한 강력한 암호시스템의 구축 및 사례연구

최병선(Byoung-Son Choi),황영철(Young-Chul Hwang),이원구(Won-Goo Lee),이재광(Jae-Kwang Lee) 한국멀티미디어학회 2003 한국멀티미디어학회 학술발표논문집 Vol.2003 No.2

2022 Internationalization Strategy of FIR (Fourth Industrial Review)

Jin-Hwang Kim,Byoung-Goo Kim 한국유통학회 2022 International Forum on Business Convergence (IFBC) Vol.2022 No.-

자간전증 임부의 혈청내 산화질소와 혈소판 활성화인자의 변화

제구화(Goo Hwa Je),이병재(Byoung Jae Lee),황태웅(Tae Woong Hwang),백동훈(Dong Hoon Baek),차문석(Moon Seok Cha) 대한산부인과학회 2002 Obstetrics & Gynecology Science Vol.45 No.7

목적 : 자간전증 환자들의 말초 혈액 내에서 산화질소 (Nitric oxide, NO)와 혈소판 활성화인자 (Platelet activating factor, PAF)의 농도를 측정하여 정상 임신과의 차이를 알아보고자 하였다. 방법 : NO의 농도는 Stuehr의 방법을 사용하여 측정하였고, PAF의 농도는 [3H]PAF scintillation proximity assay (SPA) system (Amersham Pharmacia Biotech)로 측정되었다. 결과 : NO의 농도는 정상 임신군 2.036±0.744 umol/L, 경증 자간전증 5.891±0.481 umol/L, 중증 자간전증 5.535±0.343 umol/L로 측정되어 정상 임신군에 비해 자간전증에서 높은 결과를 보였고 (p<0.05), 경증과 중증의 자간전증 임부간에는 통계학적으로 유의한 차이가 없었다 (p>0.05). PAF의 농도는 정상 임신군 435.8±59.5 ng/㎖, 경증 자간전증군 789.1±63.9 ng/㎖, 중증 자간전증 928.9±32.3 ng/㎖로 측정되어 정상 임신군에 비해 자간전증에서 높게 측정되었고 (p<0.05), 경증과 중증의 자간전증 임부간에는 통계학적으로 유의한 차이가 없었다 (p>0.05). NO와 PAF농도간에의 상관계수 (R)는 0.44012 (p<0.05)로 유의한 양적 상관관계를 보였다. 출생시 태아 체중은 정상 임신군 3242.5±374.1 gm, 경증 자간전증 2195.6±630.3 gm, 중증 자간전증 1655.9±557.9 gm으로 각 군 상호간에 통계학적으로 유의한 차이를 보였다 (p<0.05). NO와 출생시 태아 체중간에의 상관계수 (R)는 -0.59237 (p<0.05)로 유의한 음적 상관관계가 있었고, PAF와 출생시 태아 체중간에의 상관계수 (R)는 -0.33906 (p<0.05)로 유의한 음적 상관관계가 있었다. 결론 : NO와 PAF는 자간전증의 병태생리에 관여할 것으로 사료되며, PAF는 자간전증의 조기발견에 유용한 예측 인자로서 사용할 수 있을 것으로 사료된다. Objective : The aim of this study is to determine whether any association exists between preeclampsia and the maternal serum level of nitric oxide (NO) and platelet activating factor (PAF). Methods : NO concentrations were measured using Stuehr`s method and PAF concentrations were measured with [3H]PAF scintillation proximity assay (SPA) system (Amersham Pharmacia Biotech). Data were analyzed with SAS windows version 6.12, with significance established at p<0.05. Results : The mean (±SD) maternal serum concentrations of NO were significantly higher in the group with severe preeclampsia (5.535±0.343 ug/㎖) and mild preeclampsia (5.891±0.481 ug/㎖) than in the normotensive pregnancy group (2.036±0.744 ug/㎖) (p<0.05). The mean (±SD) maternal serum concentrations of PAF were significantly higher in the group with severe preeclampsia (928.9±32.3 ng/㎖) and mild preeclampsia (789.1±63.9 ng/㎖) than in the normotensive pregnancy group (435.8±59.5 ng/㎖) (p<0.05). The mean birth weight was lower in the mild and severe preeclampsia groups than in the normotensive pregnancy group (p<0.05). Conclusion : Maternal serum NO and PAF concentrations were more increased in preeclampsia than normotensive pregnancy group. NO may therefore serve as compensatory mechanism for vasoconstriction of preeclampsia and PAF as a marker for the risk of preeclampsia.

지역자활센터 팀장의 서번트리더십이 조직몰입과 경영성과에 미치는 영향

황복주(Hwang, Bok Ju),이상구(Lee, Sang Goo),김병기(Kim, Byoung Ki) 한국서비스경영학회 2020 서비스경영학회지 Vol.21 No.5

This study aims to test whether the residents participating in the community self-sufficiency center are aware of the team leader"s Servant Leadership and whether it affects the organizational commitment and the management performance of the local self-sufficiency center project group. In order to achieve these research objectives, this study surveyed 254 participants of the community self-sufficiency center and tested the hypothesis by analyzing the structural equation model. The servant leadership of community self-sufficiency center team leader had a positive effect on participants" resilience and workplace spirituality, organizational commitment. Resilience and workplace spirituality of participants in the community self-sufficiency center had a positive effect on organizational commitment. Resilience and workplace spirituality, organizational commitment of participants in the community self-sufficiency center had a positive effect on management performance. However, the servant leadership of community self-sufficiency center team leader did not affect the management performance of the business group.

Effects of multi-layer graphene capping on Cu interconnects

Kang, Chang Goo,Lim, Sung Kwan,Lee, Sangchul,Lee, Sang Kyung,Cho, Chunhum,Lee, Young Gon,Hwang, Hyeon Jun,Kim, Younghun,Choi, Ho Jun,Choe, Sun Hee,Ham, Moon-Ho,Lee, Byoung Hun IOP Pub 2013 Nanotechnology Vol.24 No.11

<P>The benefits of multi-layer graphene (MLG) capping on Cu interconnects have been experimentally demonstrated. The resistance of MLG capped Cu wires improved by 2–7% compared to Cu wires. The breakdown current density increased by 18%, suggesting that the MLG can act as an excellent capping material for Cu interconnects, improving the reliability characteristics. With a proper process optimization, MLG capped Cu interconnects could become a promising technology for high density back end-of-line interconnects.</P>