• 한국정보과학회논문지:시스템및이론
• /
• 제30권10호
• /
• pp.533-543
• /
• 2003

클러스터에 대한 관심이 증가함에 따라 클러스터의 고가용성(high availability)을 보장하기 위한 그룹 통신 시스템의 연구가 활발하다. 하지만 클러스터를 이용한 커널 수준 응용 프로그램 개발에 활용할 수 있는 커널 수준의 그룹 통신 시스템은 전무하며, 기존에 개발되어 있는 사용자 수준 그룹 통신시스템을 그대로 커널 수준에서 사용하는 것은 무리가 있다. 본 논문에서는 클러스터의 고 가용성 보장을 위하여 리눅스 커널 상에서 구현된 그룹 통신 시스템인 KCGCS(Kernel-level Cluster Group Communication System)를 설계하고 구현하였다. KCGCS는 기존 사용자 수준의 시스템들과는 달리 경량(light weight)의 핫빗(heartbeat) 메시지와 링(ring) 구조의 핫빗 메커니즘을 사용하여 확장성 있는 장애 상황 발견 메커니즘을 구현하였다. 또한 멤버쉽 관리 측면에서 KCGCS는 중앙 집중된 기존의 방법과는 달리 분산된 코디네이터를 사용하여 신뢰성을 향상시켰다.

• International Journal of Automotive Technology
• /
• 제8권2호
• /
• pp.203-209
• /
• 2007

As the vehicle electronic control technology quickly grows and becomes more sophisticated, a more efficient means than the traditional in-vehicle driving test is required for the design, testing, and tuning of electronic control units (ECU). For this purpose, the hardware-in-the-loop simulation (HILS) scheme is very promising, since significant portions of actual driving test procedures can be replaced by HIL simulation. The HILS incorporates hardware components in the numerical simulation environment, and this yields results with better credibility than pure numerical simulations can offer. In this study, a HILS system has been developed for ESP (Electronic Stability Program) ECUs. The system consists of the hardware component, which that includes the hydraulic brake mechanism and an ESP ECU, the software component, which virtually implements vehicle dynamics with visualization, and the interface component, which links these two parts together. The validity of HIL simulation is largely contingent upon the accuracy of the vehicle model. To account for this, the HILS system in this research used the commercial software CarSim to generate a detailed full vehicle model, and its parameters were set by using design data, SPMD (Suspension Parameter Measurement Device) data, and data from actual vehicle tests. Using the developed HILS system, performance of a commercial ESP ECU was evaluated for a virtual vehicle under various driving conditions. This HILS system, with its reliability, will be used in various applications that include durability testing, benchmarking and comparison of commercial ECUs, and detection of fault and malfunction of ESP ECUs.

• The Korean Journal of Physiology and Pharmacology
• /
• 제16권3호
• /
• pp.205-209
• /
• 2012

The objective of the present study was to establish the method of measurement of hydrogen peroxide and to estimate the anti-oxidative effect of genistein in the skin. UVB induced skin oxidation and anti-oxidative effect of genistein formulations were evaluated by determining levels of hydrogen peroxide. The mechanism involved in the determination of hydrogen peroxide is based on a color reaction between ferric ion ($Fe^{3+}$) and xylenol orange, often called FOX assay and subsequent monitoring of absorbance values of the reactant at 540 nm. The reaction was to some extent pH-dependent and detection sensitivity was greatest at pH 1.75. Genistein liposomal gel demonstrated better anti-oxidative effect with regard to lowering hydrogen peroxide levels elevated by UVB irradiation compared to genistein-suspended gel. A linear relationship has been observed between anti-oxidative effect of genistein and drug deposition in the skin tissue. Genistein liposomal gel resulting in the localization of the drug in the deeper skin led to improved anti-oxidative effect compared to genistein gel. The suggested method for evaluation of oxidation of the skin can be used as a tool to screen effective anti-oxidative agents and their delivery systems acting on the skin.

• The Korean Journal of Physiology and Pharmacology
• /
• 제24권6호
• /
• pp.481-492
• /
• 2020

The present study aimed to examine the effect of allyl isothiocyanate (AITC) on chronic obstructive pulmonary disease and to investigate whether upregulation of multidrug resistance-associated protein 1 (MRP1) associated with the activation of the PARK7 (DJ-1)/nuclear factor erythroid 2-related factor 2 (Nrf2) axis. Lung function indexes and histopathological changes in mice were assessed by lung function detection and H&E staining. The expression levels of Nrf2, MRP1, heme oxygenase-1 (HO-1), and DJ-1 were determined by immunohistochemistry, Western blotting and reverse transcription-quantitative polymerase chain reaction. Next, the expression of DJ-1 in human bronchial epithelial (16HBE) cells was silenced by siRNA, and the effect of DJ-1 expression level on cigarette smoke extract (CSE)-stimulated protein degradation and AITC-induced protein expression was examined. The expression of DJ-1, Nrf2, HO-1, and MRP1 was significantly decreased in the wild type model group, while the expression of each protein was significantly increased after administration of AITC. Silencing the expression of DJ-1 in 16HBE cells accelerated CSE-induced protein degradation, and significantly attenuated the AITC-induced mRNA and protein expression of Nrf2 and MRP1. The present study describes a novel mechanism by which AITC induces MRP1 expression by protecting against CS/CSE-mediated DJ-1 protein degradation via activation of the DJ-1/Nrf2 axis.

• 한국가스학회지
• /
• 제7권2호
• /
• pp.7-13
• /
• 2003

본 연구에서는 국내 휘발성 유기화합물질의 주요 취급시설에 대한 조사를 통하여 배출원별 배출메카니즘을 정립하고, 새로운 배출량산정모델을 제안하였다. 또한 각 배출원에 적용가능한 배출저감기술과 각 기술의 경제성 평가기법을 제안하였다. 여기에 배출원 DB, 화학물질물성치 DB, 기상정보 DB, 배출계수 DB 등의 정보를 연계하여 휘발성유기화합물질 배출량산정 및 관리 소프트웨어 VEER(VOCs Emission Estimation and Reduction)를 개발하였다. 결국 본 연구를 통해 개발된 VEER를 이용하여, 휘발성 유기화합물질 취급업체, 관리기관, 연구기관 등에서 쉽고 정확하게 배출원 인벤토리를 구축하고, 배출량을 산정하며, 계산된 결과를 바탕으로 각 배출원의 배출유량과 농도에 적합한 휘발성 유기화합물질 배출 저감기술을 선택하고, 여러 저감기술들에 대한 경제성을 평가함으로써, 저비용의 배출량 저감 및 배출원 관리기술을 선택하고, 설계할 수 있을 것으로 기대된다.

• Parasites, Hosts and Diseases
• /
• 제54권5호
• /
• pp.555-563
• /
• 2016

For several years, we have conducted a series of studies on the patterns of ancient parasitism prevailing in the soil of rural and urban areas of past Kingdom of Korea. Actually, during our survey of paleoparasitology in archaeological sites of Korean peninsula, numerous ancient parasite eggs were discovered in the samples from the city districts of Hansung (Joseon) and Buyeo (Baikje), the palace moat at Gyeongju (Silla), shell-midden site at Bonghwang-dong (Silla to Joseon), and the reservoir found in Hwawangsansung fortress (Silla). By the paleoparasitological studies, with respect to parasitism in the high-density populations of ancient towns and cities, we have managed to catch glimpses of the patterns prevalent therein: a serious parasitic contamination of the soil in ancient urban areas, but not in rural areas of the past. Our historical research also proposed the plausible mechanism of parasite infection very serious indeed among urban populations in Korean history. Although city dwelling doubtless has accrued significant benefits for people and populations with agriculture, it can be equally supposed that living in such highly populated areas might have facilitated the spread of parasite infection.

• Molecules and Cells
• /
• 제38권1호
• /
• pp.26-32
• /
• 2015

Toll-like receptors (TLR) 7 and 9 transduce a cellular signal through the MyD88-dependent pathway and induce the production of inflammatory mediators against microbial nucleotide components. The repeated stimulation of TLR4 leads to endotoxin tolerance, but the molecular mechanisms of tolerance induced through the costimulation of individual TLR has not yet been established, although endosomal TLRs share signaling pathways with TLR4. In the present study, mouse macrophages were simultaneously stimulated with the TLR7 agonist, gardiquimod (GDQ), and the TLR9 agonist, CpG ODN 1826, to examine the mechanism and effector functions of macrophage tolerance. Compared with individual stimulation, the costimulation of both TLRs reduced the secretion of TNF-${\alpha}$ and IL-6 through the delayed activation of the NF-${\kappa}B$ pathway; notably, IL-10 remained unchanged in costimulated macrophages. This tolerance reflected the early induction of suppressor of cytokine signaling-1 (SOCS-1), according to the detection of elevated TNF-${\alpha}$ secretion and restored NF-${\kappa}B$ signaling in response to the siRNA-mediated abrogation of SOCS-1 signaling. In addition, the restimulation of each TLRs using the same ligand significantly reduced the expression of both TLRs in endosomes. These findings revealed that the costimulation of TLR7 and TLR9 induced macrophage tolerance via SOCS-1, and the restimulation of each receptor or both TLR7 and TLR9 downregulated TLR expression through a negative feedback mechanisms that protects the host from excessive inflammatory responses. Moreover, the insufficient and impaired immune response in chronic viral infection might also reflect the repeated and simultaneous stimulation of those endosomal TLRs.

• 대한기계학회논문집
• /
• 제16권3호
• /
• pp.598-607
• /
• 1992

본 연구에서는 고온중 장시간 사용중에 일어나는 야금학적 성질의 변화의 추 원인인 특정 탄화물을 비파괴적으로 검출하기 위해, 최근에 연구 되고 있는 전기화학 적 방법을 응용하기 위한 기초연구이다. 한편으로는 비파괴적 방법의 실험실적 연구 를 현장에 응용시키기 위한 시도를 행하고, 본 연구 결과를 이용한 향후 설비 진단 시 스템의 개요를 고찰해 보인다.

• 한국산학기술학회논문지
• /
• 제13권8호
• /
• pp.3532-3536
• /
• 2012

난자 세포의 정상적인 성숙과정을 이해하려면 모계유래 유전자 발현 증가의 분자 생물학적 기전을 밝혀내야 한다. 이것은 모계 유전자의 염기서열의 변화와 밀접한 관계가 있다. 전 연구결과에 의하면 돼지 난자 체외 성숙과정에서의 모계 유전자 mRNA 발현은 통상적으로 poly(A) 꼬리 길이와 아데닐산 중합반응에 의하여 검증된다. 하지만 포유동물 체외성숙 과정에서는 아직까지 밝혀진 것이 없다. 따라서 본 연구목적은 성숙단계 난모세포에서의 분자생물학적 기전을 해명하고자, 4개의 중요한 모계유전자발현을 real-time PCR기법으로 확인하여 poly(A) 꼬리 길이와 아데닐산중합반응의 변화를 확인하였다. 본 연구에서 접합체 유전자 활성화 단계에서 모계 유전자의 비정상적인 발현과 이것에 상응하는 단백질 수준의 억제는 일부 혹은 대부분 유전자 손실에 의하여 초래된 것임을 알 수 있었다. 따라서 이상적인 모계 유전자 발현은 난자 세포의 성숙 및 더 나가서 초기 배아 발달에 중요한 역할을 하는 것임을 확인 하였다.

• Animal Bioscience
• /
• 제34권11호
• /
• pp.1766-1775
• /
• 2021

Objective: The oxidative stress status and changes of chicken ovary tissue after shading were studied, to determine the mechanism of the effect of shading on follicular development. Methods: Twenty healthy laying hens (40 weeks old) with uniform body weight and the same laying rate were randomly divided into two groups (the shading group and normal light group). In the shading group, the cage was covered to reduce the light intensity inside the cage to 0 without affecting ventilation or food intake. The normal lighting group received no additional treatment. After 7 days of shading, oxidative stress related indicators and gene expression were detected. Results: Analysis of paraffin and ultrathin sections showed that apoptosis of ovarian granulosa cells (GCs) increased significantly after light shading. Enzyme linked immunosorbent assay results revealed that the levels of total antioxidant capacity, malondialdehyde, superoxide dismutase (SOD), glutathione, catalase (CAT), and other substances in the sera, livers, ovaries, and follicular GCs of laying hens increased significantly after shading for 7 days; and reactive oxygen species (ROS) levels in the livers of laying hens also increased significantly. ROS in the serum, ovarian and GCs also increased. After shading for 7 days, the levels of 8-hydroxy-2 deoxyguanosine in the sera and ovarian tissues of laying hens increased significantly. Cell counting kit-8 detection showed that the proliferation activity of GCs in layer follicles decreased after shading for 7 days; the expression level of the anti-apoptotic gene B-cell lymphoma-2 in ovarian tissue and follicular GCs was significantly reduced, and the expression levels of pro-apoptotic caspase 3 (casp3), and SOD, glutathione peroxidase 2 (GPX2), and CAT were all significantly increased. Conclusion: Oxidative stress induced by shading light has a serious inhibitory effect on follicular development during reproduction in laying hens.