• 설비공학논문집
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• 제26권6호
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• pp.257-262
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• 2014

This paper describes an experimental study for heating performance that can be used in R-134a automobile heat pump systems. The heat pump system is widely studied for heating system in zero-emission vehicles to attain both the small power consumption and the effective heating of the cabin. This paper presents the experimental results of the influence on heating capacity and coefficient of performance of heat pump system. Tests were performed with different sizes of internal and external heat exchangers, and refrigerant flow rate was also considered in two-way flow devices. In addition, the heat, air, and water sources with the heat pump system were examined. The experimental results with the heat pump system were used to analyze the impact on performances. The best combination of performance was A-inside heat exchanger, B-outside heat exchanger, and B-flow device, respectively. In addition, a water heat-source was found to give roughly 40% of better performance than an air heat-source heat pump system.

• Journal of Chest Surgery
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• 제31권4호
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• pp.398-401
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• 1998

단극유도의 심박조율기를 가진 56세 여자환자에서 관상동맥 우회로술과 승모판 치환술을 시행하였다. 이러한 단극유도 심박조율기는 심근 외의 전자기의 간섭에 대한 감수성이 높으므로 개심술시 전기소작기의 전기파에 의해 심박조율기의 조율기능이 억제될 수 있으며, 수술후 제세동기 사용할 때 영구 심박조율기에 전기 충격이 갈 수 있다. 따라서 대동맥 차단 감자를 해제한 후 심실세동없이 정상 심박동을 유도해야 한다. 본 환자에서 임시형 심방실 유도를 거치하고 임시형 심박조율기로 조율하여 심장리듬과 심기능을 유지시키면서 전기소작기를 사용할 수 있었으며, 대동맥 차단 중 전행성 및 역행성으로 혈성심정지액을 투여하고 대동맥 차단감자를 해제하기 직전에는 온혈심정지액과 온혈의 순차적인 역행성 주입으로 자연적인 심장리듬을 회복시킴으로써 제세동기 사용을 배제할 수 있었다.

• 한국지진공학회논문집
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• 제8권2호
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• pp.55-62
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• 2004

최근 구조물 진동제어 연구분야에서는 반능동형 진동제어(제진)장치어 대한 연구가 활발하게 진행되고 있다. 반능동형 제진장치는 수동형의 장점인 신뢰성과 경제성 및 능동형의 장점인 적용성(순응성)을 얻을 수 있기 때문이다. 본 연구에서는 반능동형 제진장치의 일종으로 2톤급 반능동형 오리피스 유체댐퍼를 설계ㆍ제작하여 구조물의 적용을 통해 성능을 검증하였다. 수동형 오리피스 유체댐퍼에 2단 솔레노이드 밸브를 설치하여 반능동형을 구현하였다. 단독 성능시험을 통해 동특성을 파악하고, 시험용 철골구조물 적용시험을 통해 외부하중을 받는 구조물의 진동제어용 장치로서의 가능성을 확인하였다.

• Journal of Magnetics
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• 제12권1호
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• pp.40-44
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• 2007

The Planar Hall effect in a spin valve structure has been applied as a biosensor being capable of detecting $Dynabeads^{(R)}$ M-280. The sensor performance was tested under the application of a DC magnetic field where the output signals were obtained from a nanovoltmeter. The sensor with the pattern size of $50{\times}100{\mu}m^2$ has produced high sensitivity; especially, the real-time profiles by using that sensor revealed significant performance at external applied magnetic field of around 7.0 Oe with the resolution of 0.04 beads per $\mu m^2$. Finally, a successful array including 24 patterns with the single sensor size of $3{\times}3{\mu}m^2$ has shown the uniform and stable signals for single magnetic bead detection. The comparison of this sensor signal with the others has proved feasibility for biosensor application. This, connecting with the advantages of more stable and high signal to noise of PHR sensor's behaviors, can be used to detect the biomolecules and provide a vehicle for detection and study of other molecular interaction.

• 드라이브 ㆍ 컨트롤
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• 제18권3호
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• pp.1-7
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• 2021

In a hydraulic control system, since a hydraulic cylinder drives a relatively large mass of an object, an external load force acts as a disturbance on the control performance of the system. Additionally, as the hydraulic system is used for a long period, there are disturbances that occur gradually, such as a drop in supply pressure because of abrasion of the pump, oil leakage from a valve, and oil leakage from a cylinder. In this study, a state feedback controller based on a linearization technique is applied. To prevent the performance degradation of the controller from the load disturbance, an Extended Luenberger observer (ELO) is used for the Extended system. The case of using the proportional controller, which is a representative linear controller, and the result of using the controller designed in this study are compared and reviewed through simulation. Also, we propose an experimental gain-setting method for a state feedback controller that can be used at industrial sites, and examine how the stability and control performance of the system changes because of the disturbance inputs through the experimental results.

• 에너지공학
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• 제25권1호
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• pp.113-121
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• 2016

고분자 전해질 연료전지는 운전온도에 따라 효율과 출력이 변화하기 때문에 $65^{\circ}C{\sim}75^{\circ}C$정도의 적정 운전온도를 유지하기 위한 냉각시스템을 필요로 한다. 따라서 PEMFC 운전온도를 유지하기 위한 냉각시스템 및 이를 위한 제어로직을 적용할 필요가 있다. HILS는 이러한 냉각시스템 제어로직을 검증하고 연구하기 위한 방법 중 하나이다. 본 논문에서는 냉각수 제어 알고리즘 연구를 위해 HILS 시스템을 구성하였다. HILS 시스템 모델은 PEMFC, 열교환기 및 온도와 관련한 외부환경 모델로 구성되며, HILS 시스템의 하드웨어는 삼방밸브, 펌프, 열교환기로 이루어진다. 이러한 HILS를 활용하여 냉각시스템 제어 효율 향상을 위한 제어우선순위 및 제어 대상온도 설정에 대한 연구를 수행하였다. 1차 냉각회로의 삼방밸브를 우선제어대상으로 설정하고, 2차 냉각회로의 온도제어성능 보정을 위해 2차 냉각회로 삼방밸브의 개도율 하한값을 PEMFC 출력과 2차 냉각회로 냉각수 온도의 함수로 작성하여 온도제어성능을 보상할 수 있도록 하였다. 그 결과 안정적인 PEMFC 온도 제어성능을 확인하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제34권1호
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• pp.35-41
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• 2011

항암 치료를 받는 환자들은 장기간의 안정적인 정맥확보를 위해 중심정맥 카테터 삽입이 점차 증가하는 추세로 장기간의 항암제 투여, 종합 비경구적 영양법, 반복적 혈액채취와 항생제 투여, 혈액 투석을 위해 시행되고 있다. 그중 주입구를 완전히 피하에 심는 피하매몰형 중심정맥포트(chemo-port)의 설치가 많이 시행되고 있다. 본 연구에서는 항암치료를 받은 환자 중 중재적 방사선과에서 전형적인 카테터 끝이 열려 있는(non-valved) 포트와 새로운 형태의 카테터 끝이 닫혀 있는(valved) 포트를 삽입했던 환자를 대상으로 발생한 합병증이나 문제점에 관한 후향적 조사를 바탕으로 올바른 피하매몰 중심정맥 포트의 선택 및 관리, 해결 방안을 모색하고자 함이다. 2006년 1월부터 2010년 5월까지 피하매몰 중심정맥포트를 삽입한 438명을 대상으로 하였다. 이중 valved 포트를 삽입한 경우는 109명이었고 non-valved 포트를 삽입한 경우는 329명이었다. 포트의 사용상의 문제점을 의뢰한 56명 중 실제로 발생된 30명의 합병증이나 문제점을 valved. non-valved 포트로 나누어 비교 평가하였다. 포트 시술 후 valved 포트에서 문제점과 합병증이 11.93%, non-valved 포트에서 문제점과 합병증이 5.17% 발생하여 상대적으로 valved 포트에서 문제가 더 많이 발생하였다. Valve사용 유무에 따른 포트 사용 시 두께가 얇은 포트의 사용을 권장하고 시술시 환자 감염이 유발하지 않게 가이드라인을 설정해야 하며 시술이후에도 포트를 사용 시 전용바늘을 사용하고 사용 후 생리식염수의 의한 관 세척 등 포트관리에 체계적인 관리가 필요하다. 추가적인 문제점이 발생 시 원인을 찾아내어 해결책을 제시하고 향후 반복적인 합병증이나 문제점이 발생하지 않게 하여 포트 삽입술의 유용성과 안전성을 증대해야 한다.

• Journal of Chest Surgery
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• 제12권3호
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• pp.281-288
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• 1979

For years, physicians and anatomists have been interested in the heart that has one functioning ventricle. Various terms have been suggested for this entity including single ventricle, common ventricle, double-inlet left ventricle, cor biatriatum triloculare, and primitive ventricle. In this report, the term "single ventricle" is utilized as suggested by Van Praagh, and is defined as that congenital cardiac anomaly in which a common or separate atrioventricular valves open into a ventricular chamber from which both great arterial trunks emerge. An outlet chamber, or infundibulum, may or may not be present and give rise to the origin of either of the great arteries. This definition excludes the entity of mitral and tricuspid atresia. An 11 year old cyanotic boy was admitted chief complaints of exertional dyspnea and frequent upper respiratory infection since 2 weeks after birth. He was diagnosed as inoperable cyanotic congenital heart disease, and remained without any corrective treatment up to his age of 11 year when he suffered from aggravation of symptoms and signs of congestive heart failure for 2 months before this admission. On 22nd of May 1979, he was admitted for total corrective operation under the impression of tricuspid atresia suggested by a pediatrician. Physical check revealed deep cyanosis with finger and toe clubbing, and grade V systolic ejection murmur with single second heart sound was audible at the left 3rd intercostal space. Development was moderate in height [135 cm] and weight[28Kg]. Routine lab findings were normal except increased hemoglobin [21.1gm%], hematocrit [64 %], and left axis deviation with left ventricular hypertrophy on EKG. Cardiac catheterization and angiography revealed 1-transposition of aorta, pulmonic valvular stenosis, double inlet of a single ventricle with d-loop, and normal atriovisceral relationship [Type III C solitus according to the classification of Van Praagh]. At operation, longitudinal incision at the outflow tract of right ventricle in between the right coronary artery and its branch [LAD from RCA] revealed high far anterior aortic valve which had fibrous continuity with mitral annulus, and pulmonic valve was stenotic up to 4 mm in diameter positioned posterolaterally to the aorta. Ventricular septum was totally defective, and one markedly hypertrophied moderator band originated from crista supraventricularis was connected down to the imaginary septum of the ventricular cavity as a pseudoseptum of the ventricle. Size of the defect was 3X3 cm2 in total. Patch closure of the defect with a Teflon felt of 3.5 x 4 cm2 was done with interrupted multiple sutures after cut off of the moderator band, which was resutured to the artificial septum after reconstruction of the ventricular septum. Pulmonic valvotomy was done from 4 mm to 11 mm in diameter thru another pulmonary arteriotomy incision, and right ventriculotomy wound was closed reconstructing the right ventricular outflow tract with pericardial autograft of 3 x 4 cm2. Atrial septal defect of 2 cm in diameter was closed with 3-0 Erdeck suture, and atrial wall was sutured also when rectal temperature reached from 24`C to 35.5`C. Complete A-V block was managed with temporary external pacemaker with a pacing rate of 110/min. thru myocardial wire, and arterial blood pressure of 80/50 mmHg was maintained with Isuprel or Dopamine dripping under the CVP of 25-cm saline. Consciousness was recovered one hour after the operation when his blood pressure reached 100 /70 mmHg, but vital signs were not stable, and bleeding from the pericardial drainage and complete anuria were persisted until his heart could not capture the pacemaker impulse, and patient died of low output syndrome 320 min after the operation.

• Journal of Chest Surgery
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• 제12권3호
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• pp.289-296
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• 1979

For years, physicians and anatomists have been interested in the heart that has one functioning ventricle. Various terms have been suggested for this entity including single ventricle, common ventricle, double-inlet left ventricle, cor biatriatum triloculare, and primitive ventricle. In this report, the term "single ventricle" is utilized as suggested by Van Praagh, and is defined as that congenital cardiac anomaly in which a common or separate atrioventricular valves open into a ventricular chamber from which both great arterial trunks emerge. An outlet chamber, or infundibulum, may or may not be present and give rise to the origin of either of the great arteries. This definition excludes the entity of mitral and tricuspid atresia. An 11 year old cyanotic boy was admitted chief complaints of exertional dyspnea and frequent upper respiratory infection since 2 weeks after birth. He was diagnosed as inoperable cyanotic congenital heart disease, and remained without any corrective treatment up to his age of 11 year when he suffered from aggravation of symptoms and signs of congestive heart failure for 2 months before this admission. On 22nd of May 1979, he was admitted for total corrective operation under the impression of tricuspid atresia suggested by a pediatrician. Physical check revealed deep cyanosis with finger and toe clubbing, and grade V systolic ejection murmur with single second heart sound was audible at the left 3rd intercostal space. Development was moderate in height [135 cm] and weight[28Kg]. Routine lab findings were normal except increased hemoglobin [21.1gm%], hematocrit [64 %], and left axis deviation with left ventricular hypertrophy on EKG. Cardiac catheterization and angiography revealed 1-transposition of aorta, pulmonic valvular stenosis, double inlet of a single ventricle with d-loop, and normal atriovisceral relationship [Type III C solitus according to the classification of Van Praagh]. At operation, longitudinal incision at the outflow tract of right ventricle in between the right coronary artery and its branch [LAD from RCA] revealed high far anterior aortic valve which had fibrous continuity with mitral annulus, and pulmonic valve was stenotic up to 4 mm in diameter positioned posterolaterally to the aorta. Ventricular septum was totally defective, and one markedly hypertrophied moderator band originated from crista supraventricularis was connected down to the imaginary septum of the ventricular cavity as a pseudoseptum of the ventricle. Size of the defect was 3X3 cm2 in total. Patch closure of the defect with a Teflon felt of 3.5 x 4 cm2 was done with interrupted multiple sutures after cut off of the moderator band, which was resutured to the artificial septum after reconstruction of the ventricular septum. Pulmonic valvotomy was done from 4 mm to 11 mm in diameter thru another pulmonary arteriotomy incision, and right ventriculotomy wound was closed reconstructing the right ventricular outflow tract with pericardial autograft of 3 x 4 cm2. Atrial septal defect of 2 cm in diameter was closed with 3-0 Erdeck suture, and atrial wall was sutured also when rectal temperature reached from 24`C to 35.5`C. Complete A-V block was managed with temporary external pacemaker with a pacing rate of 110/min. thru myocardial wire, and arterial blood pressure of 80/50 mmHg was maintained with Isuprel or Dopamine dripping under the CVP of 25-cm saline. Consciousness was recovered one hour after the operation when his blood pressure reached 100 /70 mmHg, but vital signs were not stable, and bleeding from the pericardial drainage and complete anuria were persisted until his heart could not capture the pacemaker impulse, and patient died of low output syndrome 320 min after the operation.

• 한국자기학회지
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• 제24권4호
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• pp.101-106
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• 2014

Dc 마그네트론 스퍼터링법으로 자기저항비 5.0 %와 자장감응도 1.5 %/Oe를 갖는 glass/Ta(5.8 nm)/NiFe(5 nm)/Cu(2.3 nm)/NiFe(3 nm)/IrMn(12 nm)/Ta(5.8 nm) 다층구조 GMR-SV 박막을 증착하였다. 광 리소그래피 공정으로 적혈구 직경 크기인 $7{\mu}m{\sim}8{\mu}m$ 이내의 선폭인 GMR-SV 소자를 제작하였다. 직경 $1{\mu}m$ 크기인 여러 개의 자성비드가 결합된 적혈구를 자기저항비 1.06 % 자장감응도 0.3 %/Oe를 갖는 GMR-SV 소자에 떨어뜨려 -0.6 Oe 부근에서 약 $0.4{\Omega}$과 약 0.15 %의 변화를 관찰하였다. 본 연구로부터 미크론 크기의 선폭을 갖는 GMR-SV 소자가 자성비드를 결합한 적혈구내 헤모글로빈의 새로운 자성 특성을 분석하는 바이오센서로 활용할 수 있음을 보여주었다.