• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 춘계학술대회
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• pp.78-78
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• 1995

Increasing evidence indicates that the production of nitric oxide (NO) by inducible NO synthase (NOS) is tightely regulated. Transforming growth factor-${\beta}$ (TGF-${\beta}$) is a homodimeric protein secreted during macrophage activation, but several lines of evidence suggest that TGF-${\beta}$ is selectively suppressive for macrophage NO production. We therefore reasoned that a strategy employing oligodeoxynucleotides(ODNs) complemently to TGF-${\beta}$ mRNA (antisense ODNs) might increase NO production in IFN-${\gamma}$-treated murine peritoneal macrophages. To evaluate this concept, we tested the effects of antisense ODNs targeted to TGF-${\beta}$ mRNA (25-mer ODNs complemently to TGF-${\beta}$mRNA sequences) by introducing it into the medium of cultured macrophages. Phosphorothiolation of ODNs were employed to retard their degradation. Antisense ODNs had no effect on NO production by itself, whereas IFN-${\gamma}$ alone had modest effect. When antisense ODNs were used in combination with IFN-${\gamma}$, there was a marked cooperative induction of NO production, These effects of antisense ODNs were associated with decreased TGF-${\beta}$ expression in activated macrophages. ODNs with the same nucleotides but a scrambled sequence had no effect. Adding anti-TGF-${\beta}$ antibodies to the IFN-${\gamma}$-treated macrophages mimicked the positive effect of antisense ODNs on NO production. In addition, the effects of either antisense ODNs or anti-TGF-${\beta}$ antibodies were blocked by adding TGF-${\beta}$ in cultured macrophages. These results indicate that the generation of TGF-${\beta}$ by activated macrophages provides a self-regulating mechanism by which the temporal and perhaps spatial production of NO, a reactive and potentially toxic mediator, can be finely regulated.

• Journal of Biosystems Engineering
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• 제16권3호
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• pp.228-238
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• 1991

Cam plays very important roles due to continuous requirement for the high-speed and automation of the machinery. A large number of studies of cam curve were carried out by many researchers, and CNC milling and machining center for manufacturing cam have been widely used recently. The purpose of this study was to develop a CAD/CAM system for cam using QuickBasic language in 16-bit PC for application of cam design and manufacturing. Results obtained were as follows : 1. It was possible to input data by entering cam angle and its corresponding R, from 0 to 360 deg. of cam angle. The tediousness at entering data was minimized because of the same data format for both cylindrical cam and disc cam, and free format used for data file. 2. It was possible to design cam by choosing only the number of cam curve because of developing the CAD/CAM program with dimensionless method of cam curves including widely used 19 kinds. After selecting the number of the cam curve, the CAD/CAM system automatically shows the characteristics of cam motion enough to help a designer to decide : displacement, velocity, acceleration and jerk. 3. It was possible to execute, in an efficient way, both the cam profile synthesis and the generation of NC program for CNC machining center by using the input data. 4. This NC program generated by the CAD/CAM system developed here, was evaluated as positive in relation with actual manufacturing experiments and thought to be useful in its application without any modification. It can be said that this CAD/CAM system could be used by the beginners to design and manufacture the cam automatically as the system consists of very simple dialogue methods. In addition, self-developed QuickBasic would be would used as a basic tool for further stuides in this area of research, together with application.

• 융합보안논문지
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• 제13권2호
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• pp.185-193
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• 2013

베이비부머들의 대량 퇴직은 우리사회를 급속한 고령화 사회를 만들고 이를 부양하는 젊은 세대들에게 부담을 주는 원인이 되고 있다. 그중 군인 퇴직자들은 국가에만 너무 의존하지 말고 자구책을 강구해야 할 필요성이 있다. 현재 평균 수명 80세인 현실을 감안하면 연금만 가지고 생활하기에는 너무 긴 생이고 이에 대한 국가 부담도 크다. 따라서 50-60대인 군인 퇴직자들은 아직 일할 수 있는 시기임을 인식하여 경제활동을 적극적으로 할 수 있는 자세를 가져야 한다, 국가에서는 군인연금에 의존하는 기간을 짧게 하면서 일 할 수 있는 기회를 제공해 줄 수 있는 방안들을 연구할 필요성 대두되었다. 국가를 위해 헌신한 군인 퇴직자들에 대한 노후 일자리 제공 등 경제활동에 속적으로 참여할 수 있는 다양한 프로그램을 제시하여 이들에게 군인연금 의존도를 낮추고 건전한 인생 2막을 펼칠 수 있도록 현실성 있는 대책이 필요하다.

• 한국초전도ㆍ저온공학회논문지
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• 제16권4호
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• pp.21-25
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• 2014

In order to develop 2nd generation (2G) high-temperature superconducting (HTS) wires as commercial products, it is necessary to perform a high speed investigation of their superconducting performance. Room-temperature and non-contact optical scanning tools are necessary to verify the microstructure of the superconducting materials, the current flow below the critical temperature, and the critical current density. In this paper, we report our results of an inspection of the electrical transport properties of coated conductors. The samples that we used in our study were highly qualified rare-earth based coated conductors produced via co-evaporation, and $SmBa_2Cu_3O_{7-y}$ (SmBCO) was the superconducting materials used in our studies. A film grown on IBAD-MgO templates shows larger than 400 A/cm at 77 K and a self-field. The local transport properties of the films were investigated by room-temperature imaging by thermal heating. The room-temperature images show structural inhomogeneities on the surface of the films. Bolometric response imaging via low-temperature bolometric microscopy was used to construct the local current mapping at the surface. These results indicate that the non-uniform regions on the surface disturb the current flow, and laser scanning images at room-temperature and at a low-temperature suggest a correlation between the structural properties and transport properties. Thus this method can be effective to evaluate the quality of the coated conductors.

• 한국게임학회 논문지
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• 제12권4호
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• pp.65-75
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• 2012

본 연구는 Xbox-360게임 "댄스센트럴"을 통해 댄스게임의 신체적 정서적 무용교육효과를 살펴보았다. 이에 질적연구 방법 중 사례연구방법을 선정하여 댄스게임 무경험자이자 N세대에 속하는 성인 8인을 동일집단대상으로 연구하였다. 연구는 2011년 7월 18일부터 8월 15일까지 5주 동안 총 15회 댄스게임 체험을 통해 관찰자료, 반구조화 면담, 자기보고서, 참여영상을 수집하여 분석하였다. 그 결과 신체적('선행된 리듬의 익숙함', '반복된 동작의 표현성 향상', '신체활동이 활발한 댄스게임'), 정서적('단계변화에 따른 자신감 형성과 몰입 변화', '스트레스 해소', '중독성 없는 댄스게임')으로 도출되었다.

• 한국산학기술학회논문지
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• 제10권1호
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• pp.96-103
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• 2009

본 논문은 HMm (High-speed Mobile Multimedia, 초고속 이동멀티미디어) 시스템의 서브시스템인 이동단말시스템 중 RC(Radio Control), SC(Session Control), MC(Mobility Control) 등의 계층 3(Layer 3, 이하 L3) 제어 프로토콜과 VOD, FTP, VoIP 등의 응용 서비스가 구현된 L3 이동단말 플랫폼의 연구 결과를 설명한다. 하드웨어 플랫폼은 PXA255 기반으로 다양한 인터페이스와 멀티미디어 장비들이 지원되도록 제작되었고, 자체적으로 개발된 크로스 툴체인으로 생성된 임베디드 리눅스가 설치되었으며, 이 위에 L3 제어 프로토콜과 응용 서비스가 탑재되었다. L3 이동단말 플랫폼은 HMm 시스템 테스트베드에서 호처리 뿐만 아니라 영상 지원 SIP 서비스, 웹브라우징 서비스, 스트리밍 서비스 등을 성공적으로 지원하였다. 이 플랫폼은 향후 멀티미디어 기능이 강화될 4세대 이동통신단말을 개발하는데 참고가 될 수 있을 것이다.

• 한국태양에너지학회 논문집
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• 제34권1호
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• pp.81-90
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• 2014

The Jeju-Korea power system is a small-sized network with a system demand ranging from a autumn minimum of 350MW to a summer peak of 716MW. Because Jeju island is well exposed to north-east winds with high speed, applications to connect to Jeju power system are flooded. Considering physical/environmental constraints, Jeju Self-governing Province has also target for the wind power capacity of 1,350MW by 2020. It amounts to two or three times of Jeju average-demand power and wind power limit capacity announced by Korea Power Exchange (KPX) company. Wind farm connection agreements will be signed to maximize utilization of wind resource. In spite of submarine cable HVDC connected to Korea mainland, Jeju power system is independently operated by frequency and reserve control. This study reevaluates wind power limit based on the KPX criteria from 2016 to 2020. First of all wind power generation limit are affected by off-peak demand in Jeju power system. Also the possibility capacity rate of charging wind power output is evaluated by using energy storage system (ESS). As a result, in case of using 110MWh ESS, wind power limit increases 33~55MW(30~50% of ESS), wind power constraint energy decreases from 68,539MWh to 50,301MWh and wind farm capacity factor increases from 25.9 to 26.1% in 2020.

• 산학경영연구
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• 제14권
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• pp.189-210
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• 2001

소비자 연구는 매우 다양한 방법론을 적용하는 분야로서 이론정립이나 실증분석에 대한 접근방식의 차이에 따라 positivism과 relativism에 근거한 연구로 분류할 수 있다. 객관적 현실(objective reality)의 존재여부, 실증자료의 객관성, 연구 결과의 일반화 가능성 등에 대한 가정이 서로 다른 이유로, positivism이나 relativism을 연구방법론으로 수용한 학자들 간의 긴장이 각자의 연구를 dog food managerialism (positivism에 대하여), weird science (relativism에 대하여)라는 수식어를 사용하며 비난하는 경우까지 있었다. 이 연구의 목적은 positivism과 relativism에 근거한 연구방법론의 차이를 살펴보고 절충주의의 가능성을 모색하는 것이다. 그러나 Kuhn (1970)이 지적했듯이, philosophy of science의 선택은 궁극적으로 개인적이고, 주관적인 것이기 때문에, 절충주의의 가능성을 제시하기보다는 연구주제의 선택이나 방법론에 있어서 positivism과 relativism이 상호 보완할 수 있는 부분을 제안하였다.

• 대한전자공학회논문지TC
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• 제42권9호
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• pp.49-56
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• 2005

RF 전력증폭기 및 Doherty 전력증폭기의 열 메모리 효과는 변조신호의 대역폭과 동작 전력의 레벨에 따라 민감하게 영향을 미친다. 본 논문에서는 전기적인 비선형성을 정확히 모델링하고 열 메모리 효과가 Doherty 증폭기의 왜곡형성에 어떤 영향을 미치는지에 대해 연구하였다. Doherty 증폭기의 열 메모리 특성을 모델링하기 위하여 순시적으로 소모되는 전력과 순시 접합온도의 정확한 관계식을 정립하여 제안하였다. 제안된 모델의 파라미터는 서로 다른 여기상태에 따라 전력증폭기의 특성이 결정되는데, 트랜지스터의 열 메모리 효과는 대역폭이 넓은 W-CDMA 및 UMTS 시스템에서 충분히 고려되어야 한다. 이러한 열 메모리 효과를 사전왜곡 함수에 적응하여 선형화된 전력증폭기의 출력스펙트럼에서 최대 20 dB정도의 ACLR 개선효과를 보인다. 측정결과는 60W급 LDMOS Doherty 전력증폭기로 측정하였으며, 열 메모리 보상기는 ADS로 검증하였다.

• 대한간호학회지
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• 제24권2호
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• pp.157-174
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• 1994

Women’s experience of abortion are not only widespread but also significant event in their lives. But this experience has not been a concern for professional care by health care providers, especially nurses. As professional nurses should have holistic approaches to clients, need to understand the lived experience of abortion from women’s perspectives. These Nurses must identify unique means for improving the quality of life of women. This study identified the meaning and structure of the lived experience of abortion. The participants were residents of Seoul and Kwang ju who were recruited through personal recommendation. Colaizzi’s method was used for the phenomenological analysis. The research question was aimed at revealing the covert meaning of abortion. The 14 women who had a spontaneous abortion and /or an artificial abortion and who argeed to participate in the study were informed of the purpose of the study, the possible risks and benefits of participation, the data generation method and they were assured of privacy and confidentiality. The investigator conducted in-depth unstructured interviews which were audiotaped with the permission of the participants. The investigator read the data repeatdly to identify and categorize themes and basic structural elements. Eight themes of abortion as experienced by these participants were : 1) complicated feelings about the anticipated abortion 2) feelings of fear and anxiety about the operation and complications 3) grieving related loss and injury 4) feelings of lonliness in perceiving no supportive person, 5) attributing the cause of the abortion to siginificant others or to self, 6) guilt feelings and resentment, 7) vacillating between regretting and not regretting, 8) struggling to a responsible person. Five basic structures identified were : 1) Complicated feelings 2) Feelings of loss and need for caring 3) Attributings to cause to significant others 4) Paradoxical emotion 5) Struggling to be a responsible being The significes of this study for nursing are : 1) It enables nurses and other health care providers understand more clearly the lived experience of abortion 2) It provides information which can be used in for women who experience abortion.