• Journal of Chest Surgery
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• v.31 no.1
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• pp.28-31
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• 1998

Homologous blood transfusion entails substantial risks, including allergic reactions, transmission diseases such as hepatitis, acquired immunodeficiency syndrome. Autotransfusion system is a common method of reducing the need for homologous blood transfusion during cardiac operation. Between July 1993 and July 1995, a series of 40 patients undergoing open heart surgery was selected to an autotransfusion group(n=20) or a control group(n=20). The cell saver system(AT1000, Electromedics, Englewood, CO, USA) was employed for autotransfusion. With this system, shed blood in operative field during cardiopulmonary bypass(CPB) and remained blood in cardiotomy reservior after CPB was aspirated by means of a locally heparinized collecting system. After centrifuge salvaged blood, the resulting red cell concentrate reinfused subsequently. The amounts of blood loss were 766.5$\pm$121.3 ml in cell saver group, 770.1$\pm$113.6 ml in control group, and there were no significant differences between two groups(P=NS). The amounts of blood transfused were 2.91$\pm$1.72 units in cell saver group, 4.82$\pm$1.72 units in control group. Composition of processed blood by cell saver was hemoglobin 17.4 gm%, hematocrit 56.4%, RBC 5,780,000/ul, WBC 9,900/ul, and platelet 33,000/ul. There was no complication related to cell saver. Conclusively, cell saver autotransfusion system is safe, effective method for reducing the homologous blood trasfusion in cardiac surgery.

• Korean Journal of Materials Research
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• v.13 no.5
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• pp.313-316
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• 2003

The new epitaxial base cell as a high efficiency Si solar cell was fabricated and the effect of buried contact on the cell characteristics was investigated. In our experiments, the cell with buried contact showed the open circuit voltage of 0.62 V, the short circuit current of 40 mA, the fill factor of 0.7, and the efficiency of 10% under the incident light of AM-1 100 ㎽/$\textrm{cm}^2$. The insertion of buried contact in the epitaxial base structure brought the fabricated cell to the efficiency improvement of about 33%. The cell proposed in this paper has the structural superiority in the fabrication of high efficiency solar cell due to the carrier drift transport in the optical absorption region and the formation of back surface field by $p^{－}$ $p^{+}$ epitaxial base, and the reduction of emitter series resistance by n＋ buried contact.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.425-428
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• 2011

This paper presents a micro-scale solar energy harvesting circuit with a simple MPPT control. Solar Energy is harvested using a small off-chip PV cell generating output voltages under 0.5V instead of an on-chip PV cell. A simple MPPT is implemented using a pilot PV cell and utilizing the relationship between the open-circuit voltage of a PV cell ($V_{OC}$) and its MPP voltage ($V_{MPP}$). With applying the MPPT control, the designed circuit delivers the MPP voltage to load even though the loads is heavy such that the load circuit can operate properly. The proposed circuit is designed in TSMC 0.18um CMOS process.

• Parasites, Hosts and Diseases
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• v.60 no.3
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• pp.155-161
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• 2022

All living organisms are destined to die. Cells, the core of those living creatures, move toward the irresistible direction of death. The question of how to die is critical and is very interesting. There are various types of death in life, including natural death, accidental death, questionable death, suicide, and homicide. The mechanisms and molecules involved in cell death also differ depending on the type of death. The dysenteric amoeba, E. histolytica, designated by the German zoologist Fritz Schaudinn in 1903, has the meaning of tissue lysis; i.e., tissue destroying, in its name. It was initially thought that the amoebae lyse tissue very quickly leading to cell death called necrosis. However, advances in measuring cell death have allowed us to more clearly investigate the various forms of cell death induced by amoeba. Increasing evidence has shown that E. histolytica can cause host cell death through induction of various intracellular signaling pathways. Understanding of the mechanisms and signaling molecules involved in host cell death induced by amoeba can provide new insights on the tissue pathology and parasitism in human amoebiasis. In this review, we emphasized on the signaling role of NADPH oxidases in reactive oxygen species (ROS)-dependent cell death by pathogenic E. histolytica.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.313-314
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• 2016

본 논문에서는 리튬이온(Li-Ion) 배터리 셀(Cell)의 Shock test와 Vibration test 기반 18650 원통형 셀 내부 전기적 특성 변화를 분석하였다. 전류적산법을 기반으로 방전 용량을 측정하였고, OCV(Open Circuit Voltage) 측정 및 HPPC(Hybrid Pulse Power Characterization) test를 기반으로 내부 저항을 측정하고 진동 및 충격 시험 전 후의 파라미터를 비교 분석하였다.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.194-195
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• 2013

This paper presents novel single-phase PWM AC-AC converters that can solve commutation problem in single-phase direct AC-AC converter without sensing input voltage polarity. By using the basic switching cell concept and coupled inductor, the proposed converter can be short and open-circuit without damping switching devices. A 120 W prototype is built and tested to verify performance of the proposed converter.

• International Journal of Stem Cells
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• v.15 no.2
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• pp.113-121
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• 2022

The ultimate goal of regenerative medicine is to replace damaged cells, tissues or whole organs, in order to restore their proper function. Stem cell related technologies promise to generate transplants from the patients' own cells. Novel approaches such as blastocyst complementation combined with genome editing techniques open up new perspectives for organ replacement therapies. This review summarizes recent advances in the field and highlights the challenges that still remain to be addressed.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.663-664
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• 2016

다양한 분야에서 특정 이미지와 유사한 내용의 이미지를 찾기 위해서 이미지 유사도 기법을 지원하는 웹 또는 프로그램이 많이 사용되고 있다. 본 논문에서는 이미지 유사도 기법을 병리학 이미지에 적용하여 특정 세포를 찾는데 사용함으로써 사용자에게 정확하고 신뢰성 있는 정보를 전달하려 한다. 실제로 병리학에서 특정 세포를 찾기에는 세포의 크기가 너무 작고 모양이 일정하지 않는다는 점 때문에 유사한 세포를 찾기가 힘들다. 이를 해결하기 위해 Leveling과 Tiling 방식을 적용하여 데이터를 추출하고 이미지 동기화를 통해 유사도 비교 시 정확도를 높이도록 한다. 다양한 병리학 이미지 포맷을 지원하는 OpenSlide 기반의 대용량 이미지에 제안하는 방식을 적용하여 특정 세포와 유사한 부분을 찾아내는 실험을 통하여 제안하는 방식이 효율적임을 보인다.

• The Transactions of the Korea Information Processing Society
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• v.5 no.10
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• pp.2627-2640
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• 1998

In this paper, we analyze the performance of the virtual cell system[1] for the transmission of IP datagrams in mobile computer communications. A virtual cell consistsof a group of physical cells shose base stationsl are implemented b recote bridges and interconnected via high speed datagram packet switched networks. Host mobility is supported at the data link layer using the distributed hierachical location information of mobile hosts. Given mobility and communication ptems among physical cells, the problem of deploying virtual cells is equivalent to the optimization cost for the entire system where interclster communication is more expesive than intracluster communication[2]. Once an iptimal partitionof disjoint clusters is obtained, we deploy the virtual cell system according to the topology of the optimal partition such that each virtual cell correspods to a cluser. To analyze the performance of the virtual cell system, we adopt a BCMP open multipel class queueing network model. In addition to mobility and communication patterns, among physical cells, the topology of the virtual cell system is used to determine service transition probabilities of the queueing network model. With various system parameters, we conduct interesting sensitivity analyses to determine network design tradeoffs. The first application of the proposed model is to determine an adequate network bandwidth for base station networking such that the networks would not become an bottleneck. We also evaluate the network vlilization and system response time due to various types of messages. For instance, when the mobile hosts begin moving fast, the migration rate will be increased. This results of the performance analysis provide a good evidence in demonsratc the sysem effciency under different assumptions of mobility and communication patterns.

• BMB Reports
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• v.48 no.3
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• pp.178-183
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• 2015

Dendritic cells play an important role in determining whether na${\ddot{i}}$ve T cells mature into either Th1 or Th2 cells. We determined whether heat-shock protein X (HspX) purified from Mycobacterium tuberculosis regulates the Th1/Th2 immune response in an ovalbumin (OVA)-induced murine model of asthma. HspX increased interferon-gamma, IL-17A, -12 and transforming growth factor (TGF)-${\beta}$ production and T-bet gene expression but reduced IL-13 production and GATA-3 gene expression. HspX also inhibited asthmatic reactions as demonstrated by an increase in the number of eosinophils in bronchoalveolar lavage fluid, inflammatory cell infiltration in lung tissues, airway luminal narrowing, and airway hyper-responsiveness. Furthermore, HspX enhanced OVA-induced decrease of regulatory T cells in the mediastinal lymph nodes. This study provides evidence that HspX plays critical roles in the amelioration of asthmatic inflammation in mice. These findings provide new insights into the immunotherapeutic role of HspX with respect to its effects on a murine model of asthma.