• Journal of Communications and Networks
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• 제11권2호
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• pp.187-195
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• 2009

The application of mathematical analysis to the study of wireless ad hoc networks has met with limited success due to the complexity of mobility, traffic models and the dynamic topology. A scenario based universal mobile telecommunications system (UMTS) time division duplex (TDD) opportunistic cellular system with an ad hoc behaviour that operates over UMTS frequency division duplex (FDD) licensed cellular network is considered. In this paper, we present a new routing metric which overall improves system performance in terms of interference and routing which operate in an ad hoc network in an opportunistic manner. Therefore we develop a simulation tool that addresses the goal of analysis and assessment of UMTS TDD opportunistic radio system with ad hoc behavior in coexistence with a UMTS FDD primary cellular networks.

• Genomics & Informatics
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• 제7권2호
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• pp.111-121
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• 2009

Cell membrane proteins play crucial roles in the cell's molecular interaction with its environment and within itself. They consist of membrane-bound proteins and many types of transmembrane (TM) proteins such as receptors, transporters, channel proteins, and enzymes. Membrane proteomes of cellular organisms reveal some characteristics in their global topological distribution according to their evolutionary positions, and show their own information transfer complexity. Predicted transmembrane segments (TMSs) in membrane proteomes with HMMTOP showed near power-law distribution and frequency characteristics in 6-TMS and 7-TMS proteins in prokaryotes and eukaryotes, respectively. This reaffirms the important roles of membrane receptors in cellular communication and biological evolutionary history.

• 한국소음진동공학회논문집
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• 제17권12호
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• pp.1246-1253
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• 2007

The recent issue of optical pickup actuators is to apply optical storage devices to mobile devices such as a cellular phone and PDA. It requires actuators to become smaller than conventional types. As the size becomes smaller, the magnetic force is reduced and the assembly of optical pickup actuators becomes more difficult. In addition, its dynamic characteristics are changed. In this paper, methods to improve magnetic forces and dynamic characteristics are suggested and the optimal result of the plate spring design is obtained. A diamond shape magnet and the fine pattern coil (FPC) are used to improve magnetic forces and damping elements are attached to decrease the peak magnitude of the mode instead of using structural damping, mostly for the purpose of improving the accuracy of the finite element simulation. To get more stable dynamic characteristics than conventional ones, a plate spring is applied to the optical pickup actuator and it is optimized with topology and parameter optimization to obtain the concept and the detail design, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.4041-4059
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• 2019

Key establishment method based on channel reciprocity for time division duplex (TDD) system has earned a vital consideration in the majority of recent research. While most of the cellular systems rely on frequency division duplex (FDD) systems, especially the 5G network, which is not characterized by the channel reciprocity feature. This paper realizes the generation of a group secret key for multi-terminals communicated through a wireless network in FDD mode, by utilizing the nature of the physical layer for the wireless links between them. I consider a new group key generation approach, which using bitwise XOR with a modified pairwise secret key generation approach not based on the channel reciprocity feature. Precisely, this multi-node secret key agreement technique designed for three wireless network topologies: 1) the triangle topology, 2) the multi-terminal star topology, and 3) the multi-node chain topology. Three multi-node secret key agreement protocols suggest for these wireless communication topologies in FDD mode, respectively. I determine the upper bound for the generation rate of the secret key shared among multi-node, for the three multi-terminals topologies, and give numerical cases to expose the achievement of my offered technique.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2723-2725
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• 2014

Recently we have reported a novel class of anion receptors which are based on 2n-crown-n topology. Trioxane derivatives are capable of anion sensing through pure aliphatic C-H hydrogen bonding. In this work, we highlight another interesting property, i.e., they can also recognize cations as normal crown ethers (3n-crown-n topology). Since the same functional moiety can recognize anions and cations, these coronands are predicted to be amphi-ionophores. However, we could not detect cations even in the gas phase. Considering trioxane is analogous to [$1_6$]starand, this was rather counter-intuitive. The calculation results show that these coronands can detect alkali metals with very low affinity. The low affinity toward cations should be responsible for this failure of experimental detection. With careful theoretical study, we found that this low affinity toward cations could be explained by the unfavorable charge-dipolar moiety orientations as proposed by Cui et al. As in the case of [$1_6$]starand, this is an example that underscores the importance of charge-dipolar moiety orientation in supramolecular interactions.

• 한국실내디자인학회논문집
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• 제14권3호
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• pp.64-72
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• 2005

The purpose of this study is to propose a topological design principles and to analyze the space of digital architecture applying topological invariant expressive characteristics. As this study is based on topology as a science of true world's pattern, we intented to explain the concepts and provide some methods of low-level and hyperspace topological invariant Properties. Four major aspects are discussed. Those are connection theory, boundary concept, homotopy group, knot Pattern theory as topological invariant properties. Then we intented to make understand topological characteristics of the Algorithms, luring machine, cellular automata, string theory, membrane, DNA and supramolecular chemistry. In fine, the topological invariant properties of the digital architecture as genetic algorithms based on self-organization and heterogeneous networks of interacting actors can be analyzed and used as a critical tool. Therefore topology can be provided endless possibilities for architecture, designers and scientists intended in expressing the more complex and organic patterns of nature as life.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1029-1034
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• 2004

Recent engineering process requires fast development and manufacturing of the products. This paper mainly discusses the process of rapid product development (RPD) from the reverse engineering to the optimal design. A laser scanning system scans a product and the efficient data processing method reduces the scanned point data. The reduced (scanned) points model is transformed to a finite element model without the construction of a CAD model. Since CAD modeling is a time-consuming work, skipping this step can save much time. This FE model is updated from the result based on the structural characteristics from modal test of the real model. For FE model updating, Response Surface Method is adopted. Finally, the updated FE model is optimized using the reliability-based topology optimization, which is developed recently. All these processes are applied to the design of an upper part model of a cellular phone.

• 생명과학회지
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• 제29권9호
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• pp.949-954
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• 2019

세포막 단백질의 topology는 막단백질의 중요한 특징이다. 우리는 이전에 C4orf32단백질을 클로닝 하였으나, 이 단백질의 세포내 위치나 topology는 알지 못했다. 이번 연구를 통해 C4orf32는 세포내에서 소포체에 위치되는 막단백질임을 알게 되었다. C4orf32의 topology를 알기 위해 protease protection assay, fluorescence protease protection (FPP) assay, FRB/rapamycin/FKBP system을 활용하였다. Protease protection assay와 FPP assay를 적용한 결과 C-말단에 GFP를 붙인 C4orf32-GFP의 경우 GFP가 소포체의 세포질 표면에 위치함을 확인할 수 있었다. 또한, FRB/rapamycin/FKBP시스템을 이용한 실험에서 rapamycin이 처리되지 않은 경우는 mRFP-FKBP가 세포질에 위치하다가 rapamycin이 처리되면 C4orf32-GFP-FR가 위치하는 소포체로 이동함을 확인할 수 있었다. 이러한 사실은 C4orf32의 C-말단이 소포체의 세포질쪽 면에 위치한다는 사실을 말해준다. 이러한 연구를 통해 C4orf32는 Type I 소포체 막단백질에 속한다는 사실을 확인할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권5호
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• pp.874-887
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• 2011

Compared to nomadic and fixed relay stations, vehicle-mounted mobile relay stations show different characteristics caused by the time-variant topology, due to their mobility. Especially, a relay mounted in a vehicle is differentiated from nomadic or fixed relay by the restricted distance between the relay and associated mobile station and the variable density of relay deployment in a cell. In this paper, we identify the characteristics of vehicle-mounted mobile relay stations and provide some parameters that highly influence the performance of vehicle-mounted relay. Through simulation, we measure the effect of relay density, zone ratio, relay transmission power, and frame transmission mode on the performance of vehicle-mounted relay. The results show that the performance of vehicle-mounted relay is highly susceptible to the above vehicle-mounted relay-specific parameters.

• Journal of Communications and Networks
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• 제6권4호
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• pp.397-402
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• 2004

Location management is difficult in ad hoc networks due to many features such as the lack of a wired infrastructure, the scarce energy, memory and processing capabilities of nodes, and nodes’ movement which leads to a dynamic topology. These characteristics make the location management schemes designed for mobile cellular networks inefficient for ad hoc networks. New solutions for location management have therefore been proposed in the literature in the recent past. In this paper, a taxonomy of location management strategies is presented; some of the more interesting approaches proposed in the literature are critically discussed, highlighting their advantages and disadvantages.