• Molecules and Cells
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• 제41권5호
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• pp.381-389
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• 2018

ARF is a tumor suppressor protein that has a pivotal role in the prevention of cancer development through regulating cell proliferation, senescence, and apoptosis. As a factor that induces senescence, the role of ARF as a tumor suppressor is closely linked to the p53-MDM2 axis, which is a key process that restrains tumor formation. Thus, many cancer cells either lack a functional ARF or p53, which enables them to evade cell oncogenic stress-mediated cycle arrest, senescence, or apoptosis. In particular, the ARF gene is a frequent target of genetic and epigenetic alterations including promoter hyper-methylation or gene deletion. However, as many cancer cells still express ARF, pathways that negatively modulate transcriptional or post-translational regulation of ARF could be potentially important means for cancer cells to induce cellular proliferation. These recent findings of regulators affecting ARF protein stability along with its low levels in numerous human cancers indicate the significance of an ARF post-translational mechanism in cancers. Novel findings of regulators stimulating or suppressing ARF function would provide new therapeutic targets to manage cancer- and senescence-related diseases. In this review, we present the current knowledge on the regulation and alterations of ARF expression in human cancers, and indicate the importance of regulators of ARF as a prognostic marker and in potential therapeutic strategies.

• 정보처리학회논문지C
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• 제12C권2호
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• pp.223-228
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• 2005

현재 디지털 이동통신에서 사용되고 있는 DS(direct sequence)/CDMA 방식은 멀티미디어 통신과 같은 고속 데이터 전송에 적용할 경우 다중경로 페이딩 채널하에서 인접심볼간 간섭 및 다중접속간섭이 심해지는 문제점을 갖고 있다. 이러한 문제들을 보완하기 위해, 본 논문에서는 다원 접속 간섭을 억제하는 멀티코드 시스템에 인접 심볼간 간섭을 줄여주는 하이브리드 DS/FH(frequency hopping) SS(spread-spectrum)기술을 접목하여 멀티코드 하이브리드 DS/FH SS 시스템을 고안하였고, 기존의 멀티펀드 시스템이 가지는 문제점을 해결하고자 sub-code 기술을 이용하여 sub-code멀티코드 하이브리드 DS/FS SS 시스템을 제안하였다. 제안한 시스템의 성능을 분석하고자 다양한 채널 환경 하에서 컴퓨터 시뮬레이션을 실시하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.143-149
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• 2008

A numerical study was performed for a vane of a compressor with a high-turning angle and meridional divergence. At first, the effect of the suction position was discussed. Then, the optimal suction position was applied to the cascades with the aspect ratio of 2.53 and 0.3, respectively, to get the knowledge of the effect of the endwall boundary layer removal on the secondary flow along the blade height. At last, using the critical principles of the three-dimensional separation, the topological structures of the flow patterns of the body surfaces and the separation configurations were discussed in detail. The results show that the largest reduction of the total loss can be achieved when the suction slot is near the suction side. The topological structure as well as the separation configuration varies due to boundary layer removal, which restrains the flow separation at the corner and delays or depresses the separation on the suction surface. Compared with the original cascade, the cascade with the endwall boundary layer removal has a higher blade loading along the most span. Furthermore the flow loss decreases and distributes uniformly along the span.

• Structural Engineering and Mechanics
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• 제6권3호
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• pp.305-325
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• 1998

A method that determines the minimum stiffness of baracing to achieve non-sway buckling conditions at a given story level of a multi-column elastic frame is proposed. Condensed equations that evaluate the required minimum stiffness of the lateral and torsional bracing are derived using the classical stability functions. The proposed method is applicable to elastic framed structures with rigid, semirigid, and simple connections. It is shown that the minimum stiffness of the bracing required by a multi-column system depends on: 1) the plan layout of the columns; 2) the variation in height and cross sectional properties among the columns; 3) the applied axial load pattern on the columns; 4) the lack of symmetry in the loading pattern, column layout, column sizes and heights that cause torsion-sway and its effects on the flexural bucking capacity; and 5) the flexural and torsional end restrains of the columns. The proposed method is limited to elastic framed structures with columns of doubly symmetrical cross section with their principal axes parallel to the global axes. However, it can be applied to inelastic structures when the nonlinear behavior is concentrated at the end connections. The effects of axial deformations in beams and columns are neglected. Three examples are presented in detail to show the effectiveness of the proposed method.

• Steel and Composite Structures
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• 제17권5호
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• pp.573-599
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• 2014

A new type of connection for steel-concrete composite bridges was developed by the Steel Structures Laboratory of Ecole Poytechinque $F{\acute{e}}d{\acute{e}}rale$ de Lausanne. Resistance to longitudinal shear is based on the development of shear stresses in the confined interfaces which form the connection. Confinement is provided by the reinforced concrete slab which encloses the connection and restrains the uplift (lateral separation) of the interfaces by developing normal stresses. The experimental investigation of the interfaces, under static and cyclic loading, enabled the development of the laws describing the structural behaviour of each interface. Those laws were presented by the authors in previous papers. The current paper focuses on the continuity of the research. It presents the experimental investigation on the new connection by means of push-out tests on specimens submitted to static and cyclic shear loading. Investigation revealed that the damage in the connection, due to cyclic loading, is expressed by the accumulation of a residual slip. A safe fatigue failure criterion is proposed for the connection which enabled the verification of the connection for the fatigue limit state with respect to the limit of fatigue. A numerical model is developed which takes into account the laws describing the interface behaviour and the analytical expressions for the confinement effect, the latter obtained by performing finite element analysis. This numerical model predicts the shear resistance of the connection and enables to assess its fatigue limit which is necessary for the fatigue design proposed.

• The Journal of Asian Finance, Economics and Business
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• 제8권2호
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• pp.453-463
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• 2021

Economic globalization provides a good channel for the development of foreign trade around the world. Due to this background, this paper sets the Organization for Economic Co-operation and Development (OECD) countries as a sample to explore the importance of international logistics in foreign trade. An annual panel data from 2000 to 2017 will be used to conduct an empirical estimation under the panel unit root test and the fixed effect model. Foreign trade is treated as an explained variable and international logistics is treated as explanatory variables. The findings show that international logistics have a positive spillover effect on export trade and the speed of international logistics development has a regulatory effect on the relationship between both of them, which presents a U-shaped curve. When the speed of international logistics development is slow, an increase of it restrains the positive spillover effect of international logistics on export trade. However, when it rises to a certain extent, this increase releases the positive spillover effect of international logistics on export trade. As can be seen by the evidence that this paper provides, the impact of international logistics on foreign trade is dynamic. Moreover, this paper also puts forward some corresponding measures about the relationship between both of them.

• The Korean Journal of Physiology and Pharmacology
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• 제28권4호
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• pp.379-387
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• 2024

Breast cancer (BC) is most commonly diagnosed worldwide. Liquiritigenin is a flavonoid found in various species of the Glycyrrhiza genus, showing anti-tumor activity. This article was to explore the influences of liquiritigenin on the biological behaviors of BC cells and its underlying mechanism. BC cells were treated with liquiritigenin alone or transfected with oe-HSP90 before liquiritigenin treatment. RT-qPCR and Western blotting were employed to examine the levels of HSP90, Snail, E-cadherin, HSC70, and LAMP-2A. Cell viability, proliferation, migration, and invasion were evaluated by performing MTT, colony formation, scratch, and Transwell assays, respectively. Liquiritigenin treatment reduced HSP90 and Snail levels and enhanced E-cadherin expression as well as inhibiting the proliferation, migration, and invasion of BC cells. Moreover, liquiritigenin treatment decreased the expression of HSC70 and LAMP-2A, proteins related to chaperone-mediated autophagy (CMA). HSP90 overexpression promoted the CMA, invasion, and migration of BC cells under liquiritigenin treatment. Liquiritigenin inhibits HSP90-mediated CMA, thereby suppressing BC cell growth.

• 정보처리학회논문지C
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• 제10C권3호
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• pp.355-366
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• 2003

오늘날 무선 이동 망의 빠른 기술 발전으로 인해 이동 인터넷 서비스의 시장이 급속히 팽창하고 있다. 본 논문에서는 무선 이동 망에서 이동 호스트의 QoS 보장을 위한 효율적 자원 예약 프로토콜인 Proxy MRSVP(PMRSVP)를 제안한다. PMRSVP는 수정된 지역 위치등록을 이용하여 무선 이동 망에서 기존의 Best Effort 서비스의 개선책으로 제시되고 있는 프로토콜들의 문제점인 메시지 과다 발생을 줄인다. 또한, Mobile Agent(MA)들이 Corresponding Host(CH)의 프록시 역할을 하도록 함으로써 신호 메시지 발생 양과 자원 예약 비용이 MRSVP와 Hierarchical MRSVP(HMRSVP) 방법에 비해 낮다는 것을 보인다. 본 논문의 우수성을 보이기 위해 MRSVP와 HMRSVP 그리고 PMRSVP를 도메인내(intradomain)와 도메인간(interdomain)의 위치 등록 비용을 포함한 자원 예약 비용을 비교한다.

• 디지털융복합연구
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• 제13권8호
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• pp.387-400
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• 2015

연구의 목적은 국내 간호사 소진과 관련된 선행연구를 바탕으로 보호변인과 위험변인의 효과크기를 확인하는 것이다. 2005년에서 2014년 까지 석박사학위, 학술지 논문 총116편을 메타분석을 실시하여 융복합적인 결론을 제시하였다. 간호사 소진 보호변인군의 가장 큰 효과크기는 직무변인군이었으며, 하위변인은 공감만족이었다. 간호사의 소진 관련 위험변인군의 효과크기는 조직변인군이 가장 큰 변인군이었으며, 하위변인의 효과크기는 폭력반응이 가장 높았다. 본 연구 결과를 바탕으로 간호사 소진을 억제하는 보호변인을 강화하고, 소진을 유발하는 위험변인 감소를 대응하기 위해서 적절한 개입과 중재를 위한 다양한 프로그램 개발과 정책방안이 구축되어야 할 것이다.

• 한국인터넷방송통신학회논문지
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• 제15권1호
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• pp.245-251
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• 2015

이 논문에서 LED로 구동되는 LCD 표시판의 백라이트 전체 화면의 밝기를 균일하게 제어할 수 있고, 필요에 따라 전체 화면 중 각 부분의 휘도 및 색의 특성을 정밀하게 제어할 수 있는 LED 백라이트용 제어 장치 및 백라이트 용 구동 장치를 제시한다. 백라이트 제어 장치는 clock 신호에 따라 직렬 데이터를 시프트 시키면서 병렬 데이터로 변환하여 출력하는 직렬-병렬 변환 시프트 레지스터, 복수의 레지스터들, 카운터, 복수의 비교기들, 그리고 PWM 제어 신호를 출력하는 복수의 동기화 게이트들을 포함한다. 이 논문에서 백 라이트 제어 장치 및 백라이트 구동 장치는 clock 주파수를 높이지 않으면서도 높은 분해능을 갖는 PWM 제어 신호를 생성할 수 있고 양자화 잡음을 분산하여 희석시킬 수 있는 PWM 제어 회로, 백라이트 제어 장치 장치를 제시한다.