• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.628-635
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• 2013

We investigated the effects of water extracts of unripe black raspberry (UBR) and red ginseng (RG) on cholesterol synthesis, 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase activity, and expression of low-density lipoprotein (LDL) or high-density lipoprotein (HDL)-related genes in HepG2 and Caco-2 (human hepatoma and intestinal cell lines, respectively). Our results showed that cholesterol synthesis and HMG-CoA reductase activity in HepG2 cells were inhibited by UBR and RG. Further, co-treatment with UBR and RG had a greater effect than did treatment with either UBR or RG. In Caco-2 cells, treatment with UBR and RG increased the expression of LDL-regulated genes, such as LDL receptor and SREBP-2, and also upregulated the level of HDL-associated ABCA1. Moreover, co-treatment with UBR and RG appeared to be more effective than treatment with either UBR or RG. Taken together, our results indicate that UBR and RG regulate the level of HDL-associated ABCA1 via signaling pathway, thereby preventing cholesterol synthesis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.1899-1907
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• 2013

We investigated the effects of unripe black raspberry water extract (UBR-W) and oxidation-LDL treatment on cholesterol levels. Experiments using an established human hepatocellular carcinoma cell line (HepG2) showed a time-dependent increase in expression of LDL receptor after UBR-W treatment. Expression of LDL receptor-related genes, such as SREBP1 and 2, increased upon UBR-W treatment. However, expression of HDL-related genes was unaffected by UBR-W. HMG-CoA reductase activity was reduced by UBR-W treatment, whereas HMG-CoA mRNA expression significantly increased. In addition, the ApoB/ApoA1 mRNA level, which is a predictor of cardiovascular risk, was reduced in a time-dependent manner by UBR-W treatment. Macrophage-like cells (RAW 264.7) showed increased expression of ox-LDL-related genes, such as CD36, scavenger receptor-A, adipophilin, and PPAR-gamma, upon ox-LDL treatment compared to untreated control cells, and quantitative lipid analysis indicated a dramatic increase in lipid accumulation. However, UBR-W treatment significantly reduced expression of ox-LDL-related genes and largely prevented lipid accumulation. The results indicate that UBR-W mediates a cholesterol-lowering effect via inhibition of cholesterol synthesis and induction of LDL uptake through SREBP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1491-1499
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• 2014

We examined the effects of unripe black raspberry (UBR) and red ginseng (RG) extracts on cholesterol improvement in C57BL/6J mice fed a HCD (high cholesterol diet) for 12 weeks. Hepatic total lipid and total cholesterol contents were significantly induced in hyperlipidemic mice. However, supplementation with UBR, RG and simvastatin effectively reduced these lipid profiles. Further, UBR and co-treatment with UBR and RG increased expression of LDL receptor, SREBP2, and SR-B1 mRNA compared with HCD. The ApoB/ApoA1 ratio was reduced by co-treatment with UBR and RG compared to treatment with UBR. In addition, histopathologic evaluation showed that co-treatment with UBR and RG suppressed lipid accumulation as well as FAS and leptin expression in plasma. These results indicate that co-treatment with UBR and RG may be useful for the prevention of hypercholesterolemia.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.489-497
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• 2014

We examined the effects of unripe black raspberry water extract (UBR-W) on lipid metabolism and oxidative stress in mice. C57BL/6J mice were divided into 4 groups: those administered a control diet (CTL), high-fat diet (HFD), UBR-W and simvastatin for 12 weeks. In the HFD group, LDL cholesterol were significantly higher than in the CTL group. However, the UBR-W treated group showed dose-dependent reduction of plasma LDL levels. Hepatic total lipid, TC, and malondialdehyde were significantly increased in hyperlipidemic mice. However, supplementation with either UBR-W or simvastatin effectively reduced these lipid profiles and lipid peroxidation. UBR-W increased mRNA expression of the LDL receptor, sterol regulatory element binding protein 2 (SREBP2), 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase and ATP-binding cassette transporter A1 (ABCA1) compared to that observed in the HFD group. In addition, UBR-W and simvastatin showed significantly reduced oxidized LDL uptake by the scavenger receptor CD36. These results suggest that UBR-W is useful for treatment and prevention of hyperlipidemia and lipid peroxidation.

• Journal of KIISE:Information Networking
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• v.27 no.1
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• pp.76-87
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• 2000

ATM is a key technology of integration of multimedia service. Recently, Many study have been concentrated on performance testing for evaluation network performance are stronger everyday. The performance testing is on evaluation of maximal throughput of network by measuring and analyzing of various performance parameters. There are two ways to test ATM network performance; one is using QoS in cell level on the point of network's view, and the other is using metric in frame level in the point of user's view. And, the standardization process is also under way. In this paper, we derive a performance requirement of TCP in TCP/IP data transmission over ATM UBR service. By applying the derived requirements to ATM and packet networks, we evaluate the performance of TCP over UBR based on the result of our simulations. Therefore, we evaluate the result of simulation and find degradation of network throughput by interaction between TCP congestion control and ATM cell drop policy. So we suggest the accelerated Vegas that modify traditional TCP Vegas in congestion control mechanism for batter network throughput.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.362-364
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• 1998

최근의 네트워크의 특징은 '광대역 통합 서비스 네트워크'라 할 수 있다. 뿐만 아니라, 최근의 ATM연결은 점대점 연결은 물론, 점대다점 연결을 특징으로 하고 있다. 이 논문에서는 하나의 ATM 멀티캐스트 (MVCC)세션 내에서, ATM계층 상위에 TCP와 같은 LAN기반 네트워크 연동에 대해 다룬다. ATM네트워크 상에 멀티캐스트 연결을 설정할 경우, 공유 트리 방식에 의해 연결 트리를 구성하고, AAL5 계층을 사용하므로 CIP 가 발생한다. 이 문제를 해결하기 위해 ABT/IT RM셀을 이용한 블록단위의 전송을 고려한다. 또한, ATM VC 위에 LAN 기반 네트워크 연동 서비스를 제공하기 위해 UBR 클래스를 이용하게 되는데. 그 속성상 QoS를 보장하지 못하고 네트워크에 혼잡 발생시에 우선적으로 폐기되며 단지 EPD메커니즘과 같은 버퍼 관리 방식만을 사용할 뿐이다. 따라서, ABT RM 셀을 통한 블록 단위 전송을 이용하게 되면 CIP를 해결할 뿐만 아니라. 여러 응용 트래픽 유형을 고려한 스케줄링을 통해 네트워크 상에 혼잡이 발생할 경우에 UBR 트래픽이 무차별적으로 폐기되는 현상을 막고, 효율적이고 공평한 서비스를 제공할 수 있다. 이을 위해.ATM스위치 내에 하나의 멀티캐스트 세션에 대한 블록 스케줄링 알고리즘을 제안한다.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.4
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• pp.82-87
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• 1999

The Asynchronous Transfer Mode(ATM) networks are being adopted as backbones over various parts of Internet. TCP is one of the most widespread transport protocols and can be used with ATM. But, TCP shows poor end-to-end performance on ATM networks. Effective throughput of TCP over ATM can be quite low when cells are dropped at the congested ATM switch. As congested link transmits cells from corrupted packets, it wastes bandwidth and throughput becomes low. This paper examines the behavior of TCP over ATM-UBR using EPD switch in a broadband environment. As threshold value closes to the buffer size, the buffer can be used more efficiently, but more drops and retransmission occur. If the threshold value is much less than buffer size, efficiency becomes low, but few drops can be happen. Therefore, the decision of threshold value becomes important factor.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.9A
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• pp.1535-1541
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• 2001

TCP is the most widely-used transport layer protocol in current Internet, while ATM technology is used to increase the data communication speed at data link layer and network layer. In the TCP-over-ATM architecture, the most significant problems are (i) the partial packet discarding problem, and (ii) the TCP window timeout problem. Several approaches have been proposed to solve the partial packet discard problem and the timeout problem individually, but none of them considered the two problems together. In this paper, we propose an enhanced UBR+ scheme which supports fairness among the TCP connections using UBR+ scheme, and provides protection of damaged VC from the multiple packet losses in the same TCP sliding window. To analyze its performance, we simulate the proposed scheme using OPNET. The simulation results show that the proposed scheme supports fairness, and also increases the throughput by reducing the probability of multiple cell losses in the same TCP window.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.460-462
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• 2003

본 논문은 현재 18M, 마이크로소프트, SAP등이 운용하고 있는 대표적인 공용 UBR(UDDI Business Registry) 노드들과 국내에서 개발된 K-UDDI, 일본의 NTT에서 운용하는 UBR노드에 대해 각각의 특징을 서로 비교해 본다. 또한 간단한 모니터링 프로그램을 구현하여, 각각의 UDDI 비즈니스 레지스트리에 등록되고 있는 전체 비즈니스 개체와 비즈니스 서비스 수의 증감 추이를 관찰하고, 등록된 비즈니스 개체별 링크된 WSDL파일의 유효함의 여부를 실행한 결과물을 통해 현재 운용중인 공용 UDDI 레지스트리의 활성화 정도를 분석해 본다.

• Journal of the Korea Computer Industry Society
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• v.3 no.1
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• pp.95-104
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• 2002

This paper presents some studies on the Internet TCP/IP(Transmission Control Protocol-Internet Protocol) traffic over ATM(Asynchronous Transfer Mode) UBR(Unspecified Bit Rate) and ABR(Available Bit Rate) classes of service. Fuzzy logic prediction has been used to improve the efficiency and fairness of traffic throughput. For TCP/IP over UBR, a novel fuzzy logic based cell dropping scheme is presented. This is referred to as fuzzy logic selective cell drop (FSCD). A key feature of the scheme is its ability to accept or drop a new incoming packet dynamically based on the predicted future buffer condition in the switch. This is achieved by using fuzzy logic prediction for the production of a drop factor. Packet dropping decision is then based on this drop factor and a predefined threshold value. Simulation results show that the proposed scheme significantly improves TCP/IP efficiency and fairness. To study TCP/IP over ABR, we applied the fuzzy logic ABR service buffer management scheme from our previous work to both approximate and exact fair rate computation ER(Explicit cell Rate) switch algorithms. We then compared the performance of the fuzzy logic control with conventional schemes. Simulation results show that on zero TCP packet loss, the fuzzy logic control scheme achieves maximum efficiency and perfect fairness with a smaller buffer size. When mixed with VBR traffic, the fuzzy logic control scheme achieves higher efficiency with lower cell loss.