• Korean Journal of Computational Design and Engineering
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• v.5 no.4
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• pp.380-392
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• 2000

This paper proposes a qualitative reasoning approach for the spatial configuration of mechanisms that could be applied in the early phase of the conceptual design. The spatial configuration problem addressed in this paper involves the relative direction and position between the input and output motion, and the orientation of the constituent primitive mechanisms of a mechanism. The knowledge of spatial configuration of a primitive mechanism is represented in a matrix form called spatial configuration matrix. This matrix provides a compact and convenient representation scheme for the spatial knowledge, and facilitates the manipulation of the relevant spatial knowledge. Using this spatial knowledge of the constituent primitive mechanisms, the overall configuration of a mechanism is described and identified by a spatial configuration state matrix. This matrix is obtained by using a qualitative reasoning method based on sign algebra and is used to represent the qualitative behavior of the mechanism. The matrix-based representation scheme allows handling the involved spatial knowledge simultaneously and the proposed reasoning method enables the designer to predict the spatial behavior of a mechanism without knowing specific dimension of the components of the mechanism.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.1057-1060
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• 2014

Adiposity is a well-recognized risk factor of type 2 diabetes and cardiovascular disease, and recently there is increasing evidence that excess body weight is an avoidable cause of cancer, including gastrointestinal, endometrial, esophageal adenocarcinoma, colorectal, postmenopausal breast, prostate, and renal malignancies. The mechanisms whereby adiposity is associated with tumor development remains not well understood. There are some most studied hypothesized mechanisms such as, high levels of insulin and free levels of insulin-like growth factors, sex hormones, adipocytokines, and inflammatory cytokines, adiposity-induced hypoxia, and so on. The potential mechanisms and conclusions in adiposity associated with increased risk for developing malignancy, and the underlying cellular and molecular mechanisms will be studied very well in the near future.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.2
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• pp.315-320
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• 2008

This study investigated the signaling mechanisms contributed to the vasodilatory effects of HMC05, a herbal prescription. HMC05 acted in an endothelium-independent manner. To elucidate the fundamental mechanisms of its vascular actions, we focused on the signaling molecules involved in actin-myosin filament regulation including 20 kDa myosin light chains (LC20), Rho-associated kinase (ROCK), PKC, JNK and extracellular signal-regulated protein kinase (ERK) in the endothelium-denuded thoracic aorta or isolated smooth muscle cells (SMCs). It lowered the phosphorylation level of LC20 and showed that ROCK, ERK, JNK and $PKC{\alpha}$ pathways played important roles in the effects, as confirmed by the observations with a specific inhibition or activation, and with the activity and the subcellular localization of these molecules. In particular, HMC05 dramatically inhibited the activity of ERK and the downstream signaling of ROCK. It also changed the subcellular localization of the phophorylated $PKC{\alpha}$ as well as the amount of phosphorylation. Taken together, these data indicate that the vascular relaxation effects of HMC05 are attributed to the regulation of these signaling mechanisms.

• Journal of Biosystems Engineering
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• v.38 no.2
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• pp.129-137
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• 2013

Purpose: Modeling has been used for elucidating the mechanism of complex biosystems. In spite of importance and uniqueness of adolescent calcium (Ca) metabolism characterized by a threshold Ca intake, its regulatory mechanism has not been covered and even not proposed. Hence, this study aims at model-based proposing potential mechanisms regulating adolescent Ca metabolism. Methods: Two different hypothetic mechanisms were proposed. The main mechanism is conceived based on Ca-protein binding which induces renal Ca filtration, while additional mechanism assumed that active renal Ca re-absorption regulated Ca metabolism in adolescents. Mathematical models were developed to represent the proposed mechanism and simulated them whether they could produce adolescent Ca profiles in serum and urine. Results: Simulation showed that both mechanisms resulted in the unique behavior of Ca metabolism in adolescents. Based on the simulation insulin-like growth factor-1 (IGF-1) is suggested as a potential regulator because it is related to both growth, a remarkable characteristic of adolescence, and Ca metabolism including absorption and bone accretion. Then, descriptive modeling is employed to conceptualize the hypothesized mechanisms governing adolescent Ca metabolism. Conclusions: This study demonstrated that modeling is a powerful tool for elucidating an unknown mechanism by simulating potential regulatory mechanisms in adolescent Ca metabolism. It is expected that various analytic applications would be plausible in the study of biosystems, particularly with combination of experimental and modeling approaches.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.197-206
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• 2001

The depletion of stratospheric ozone is regarded as a major environmental threat to plant growth and ecosystem. The ozone depletion has caused plants to be exposed to an increased penetration of solar ultraviolet-B (UV-B) radiation in the 280-320 nm wavelength range. Enhanced UV-B radiation may have influence on plants biological functions in many aspects including inhibition of photosynthesis, DNA damage, lipid peroxidation, changes in morphology, phenology, and biomass accumulation. To cope with the damage by UV radiation, plants have evolved to have protective mechanisms, such as photorepair, accumulation of UV-absorbing compounds, leaf thickening and activation of antioxidative enzymes. The objective of this review is to address the effects of enhanced UV-B on plant growth, UV-B action mechanisms and protection and protection mechanisms in plants.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.25-26
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• 2007

At the time when nanostructured materials (NSMs) are becoming a major focus of materials research, the attention of researchers is turning more to their mechanical performance. In contrast with conventional coarse grained materials, which are either strong or ductile, but rarely both at the same time, it is expected that with NSMs both high strength and ductility can be achieved and confirmed by several experimental studies. In spite of the significant interest and efforts in the mechanical properties of NSMs, deformation mechanisms during plastic deformation as well as elastic deformation are not well established yet. In this talk, the deformation mechanisms of NSMs under various grain sizes, temperatures and strain rates were investigated. It is based on recent modelling that appears to provide a conclusive description of the phenomenology and the mechanisms underlying the mechanical properties of NSMs. Based on the theoretical model that provides an adequate description of the grain size dependence of elasticity and plasticity covering all grain size range from coarse down to the nanoscale, the tensile deformation response of NSMs, especially focusing on the deformation mechanisms was investigated.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.4
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• pp.41-48
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• 2005

In recent years, the need for multi-stage gear drives which highly reduce output speed has been increased. However, the design of multi-stage gear drives has been carried out by a limited number of experts. The consideration for the direction of input and output axes also makes their design very difficult. The purpose of this study is to develop an algorithm for automatically generating complex multi-stage gear drives and to implement a design supporting system for multi-stage gear drives. There are 4 stages in the proposed algorithm, and major design parameters, such as the direction of input and output axes, reduction ratio, etc. are set up in the first stage. In the second stage, all mechanisms are generated, and various rules are applied to select feasible mechanisms. In the third stage, the gear ratio of each stage is divided from total gear ratio. Next, the specifications of gears for feasible mechanisms are calculated and their bending strength and surface durability are estimated. In the forth stage, appraised indexes are calculated and provided to support the estimation of the generated gear drives.

• Journal of Ginseng Research
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• v.36 no.1
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• pp.16-26
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• 2012

Ginseng is one of the most widely used herbal medicines and is reported to have a wide range of therapeutic and pharmacological applications. Ginseng may also be potentially valuable in treating cardiovascular diseases. Research concerning cardiovascular disease is focusing on purified individual ginsenoside constituents of ginseng to reveal specific mechanisms instead of using whole ginseng extracts. The most commonly studied ginsenosides are $Rb_1$, $Rg_1$, $Rg_3$, $Rh_1$, Re, and Rd. The molecular mechanisms and medical applications of ginsenosides in the treatment of cardiovascular disease have attracted much attention and been the subject of numerous publications. Here, we review the current literature on the myriad pharmacological functions and the potential benefits of ginseng in this area. In vitro investigations using cell cultures and in vivo animal models have indicated ginseng's potential cardiovascular benefits through diverse mechanisms that include antioxidation, modifying vasomotor function, reducing platelet adhesion, influencing ion channels, altering autonomic neurotransmitters release, and improving lipid profiles. Some 40 ginsenosides have been identified. Each may have different effects in pharmacology and mechanisms due to their different chemical structures. This review also summarizes results of relevant clinical trials regarding the cardiovascular effects of ginseng, particularly in the management of hypertension and improving cardiovascular function.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5B
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• pp.356-363
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• 2008

The decision of the USA to found the USF(Universal Service Fund) in 1983, which was aiming to support basic telecommunication services provision at affordable price in rural and high cost areas, has triggered many countries to introduce universal service support mechanisms. Korea has been also operating a universal service support mechanism since 2000 but there are lively controversies on the change of the existing support mechanism. This paper, first, will review universal service support mechanisms in major countries including USA, EU, Chile, Peru and Japan. Second, this paper will classify types of the mechanisms and review merits and demerits of the mechanisms. Finally, this paper will derive some implications for the improvement of domestic Mechanism.

• Journal of Information Technology Services
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• v.8 no.1
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• pp.165-177
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• 2009

This paper reviews diverse IP mobility and fast handover mechanisms for seamless Internet services. Especially, fast handover mechanisms for the Proxy Mobile IPv6( PMIPv6) are categorized according to their approaches. Then, a new fast handover PMIPv6(FH-PMIPv6) mechanism is proposed using only L3 signaling message exchange. In the proposed FH-PMIPv6 mechanism, only local mobility anchor(LMA) exchanges L3 signaling messages with mobility access gateways(MAGs) for the fast handover operation. That is, inter-MAG signalling messages are not required for the fast handover operation. Therefore, unlike existing fast handover mechanisms, two relevant neighbouring MAGs need not set up the security association(SA) to protect fast handover related signaling messages and share SA related information. Moreover, the L3 triggering message is defined newly by standard ICMPv6 to trigger promptly the proposed mechanism. Analysis and comparison of the handover latency are performed for the proposed mechanism and existing mechanisms, which shows that the proposed FH-PMIPv6 mechanism has the favorable performance.