• BMB Reports
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• v.44 no.2
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• pp.118-122
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• 2011

Most widely used secondary structure assignment methods such as DSSP identify structural elements based on N-H and C=O hydrogen bonding patterns from X-ray or NMR-determined coordinates. Secondary structure assignment algorithms using limited $C{\alpha}$ information have been under development as well, but their accuracy is only ~80% compared to DSSP. We have hereby developed SABA (Secondary Structure Assignment Program Based on only Alpha Carbons) with ~90% accuracy. SABA defines a novel geometrical parameter, termed a pseudo center, which is the midpoint of two continuous $C{\alpha}s$. SABA is capable of identifying $\alpha$-helices, $3_{10}$-helices, and $\beta$-strands with high accuracy by using cut-off criteria on distances and dihedral angles between two or more pseudo centers. In addition to assigning secondary structures to $C{\alpha}$-only structures, algorithms using limited $C{\alpha}$ information with high accuracy have the potential to enhance the speed of calculations for high capacity structure comparison.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.203-212
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• 2004

There is a rapidly growing demand for wireless telecommunication. The restricted number of channels is a significant bottleneck for the capacity of mobile communication systems. Consequently, when assigning the channels to the different base stations, it is desirable to reuse the same channel af much as possible. It is then important to avoid any possible interference between different mobile users, while satisfying the given demand. The objective of this thesis is to develop a hybrid heuristic algorithm to find the channel assignment method for allocating the channels in an efficient way, which does not violate the compatibility constraints. We also show several benchmarking channel assignment problems using proposed channel assignment method for validation in this thesis.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.321-333
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• 2005

With the limited frequency spectrum and an increasing demand for cellular communication services, the problem of channel assignment becomes increasingly important. However, finding a conflict free channel assignment with the minimum channel span is NP hard. As demand for services has expanded in the cellular segment, sever innovations have been made in order to increase the utilization of bandwidth. The innovations are cellular concept, dynamic channel assignment and hierarchical network design. Hierarchical network design holds the public eye because of increasing demand and quality of service to mobile users. We consider the frequency assignment problem and the base station placement simultaneously. Our model takes the candidate locations emanating from this process and the cost of assigning a frequency, operating and maintaining equipment as an input. In addition, we know the avenue and demand as an assumption. We propose the network about the profit maximization. This study can apply to GSM(Global System for Mobile Communication) which has 70% portion in the world. Hierarchical network design using GA(Genetic Algorithm) is the first three-tier (Macro, Micro, Pico) model, We increase the reality through applying to EMC (Electromagnetic Compatibility Constraints). Computational experiments on 72 problem instances which have 15${\sim}$40 candidate locations demonstrate the computational viability of our procedure. The result of experiments increases the reality and covers more than 90% of the demand.

• The KIPS Transactions:PartC
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• v.13C no.2 s.105
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• pp.167-170
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• 2006

Most wavelength assignment algorithms assume that every node has infinite ADMs and I/O blocking is excluded. Furthermore wavelengths continue to occur intermittently in the network using existing algorithms. This can result in increased link blocking under dynamic traffic circumstances. In audition, it can create time-complexity problems such as O(W $N^3$) in the worst case scenario. In this paper, we propose a new wavelength assignment algorithm which has time-complexity of O(W $N^2$) and considers both I/O and link blocking. The basic idea is to maximize the number of links where wavelengths will be assigned continuously after present assignment. As a result, the number of intermittent wavelengths is minimized, and blocking probabilities are decreased.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.211-220
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• 2013

This paper proposes an algorithm that easily finds an optimal solution for linear bottleneck assignment problems. It is either threshold or augmenting path algorithm that is generally used to solve the bottleneck assignment problem. This paper proposes a reverse-delete algorithm that follows 2 steps. Firstly, the algorithm deletes the maximum cost in a given matrix until it renders a single row or column. Next, the algorithm improves any solution that contains a cost exceeding the threshold value $c^*_{ij}$. Upon its application to 28 balanced assignment problems and 7 unbalanced problems, the algorithm is found to be both successful and simple.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.3
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• pp.339-347
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• 1993

The channel assignment problem in a mobile communication system is a NP-complete combinatorial optimization problem, in which the calculation time increases exponentially as the range of the problem is extended. This paper adapts a conventional Hopfield neural network model to the channel assignment problem to relieve the calculation time by means of the parallelism supplied from the neural network. In the simulation study, we checked the feasability of such a parallel method for the fixed channel assignment with uniform, and nouniform channel requirements, and for the dynamic channel assignment with considering continously varying channel requirements.

• Journal of Korea Multimedia Society
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• v.16 no.5
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• pp.566-576
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• 2013

In Home Area Network (HAN) of the smart grid, Power Line Communication (PLC) technology and ZigBee communication technology can be used in the communication among the Advanced Metering Infrastructure (AMI) devices. However, according to performance evaluation results of the PLC technology, we find that using the PLC technology is unsuitable for the remote meter reading service. It is worth noting that some parts of the PLC are converted to the ZigBee communication technology in Jeju, Korea. Compared with PLC, ZigBee has no restriction of the place, where the equipments can be freely set up, due to the advantage of radio communication. However, number of usable devices will impact the network performance which is depended on the address assignment. In addition, due to the restriction of transmission range among devices, it is difficult to apply the ZigBee address assignment method to the practical circumstance. In this paper, we examine the previous ZigBee address assignment schemes and the corresponding routing algorithms, and propose a novel address assignment scheme compared with the existing methods, the performance of the proposed one is improved. In particular, evaluation results show that the proposed scheme reduces the average number of hop count, the transfer time and the processing time.

• The Journal of Society for e-Business Studies
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• v.12 no.3
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• pp.235-249
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• 2007

Workflow systems are software systems that control the execution of long-term processes. Members of an organization are in charge of executing processes. A work assignment policy, i.e who should perform a certain piece of process, has to be modeled and implemented in workflow systems. Organizations may have a large variety of problems in work assignment, and it may not be feasible to devise a single model to cover all problems. In this paper, we introduce generality to work assignment design problems in workflow systems We provide a meta-model based approach which enables us to define arbitrary problem oriented work assignment policies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.832-842
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• 2006

Wireless Personal Area Networks(WAPANs) are designed for short-range ad hoc connectivity among portable devices. They have gained much attention in the industry recently. One of them, High-rate WPAN, is designed to support multimedia traffic that requires high data rates. But, High-rate WPAN standards don't specify the time slot assignment scheduling method of CAT(Channel Time Allocation). So, there has been many studies regarding time slot assignment scheduling of CAT. However, present studies involve demerits about not applying various types of errors in air interlace or having a starvation of a specific DEV(data device). In this paper, we propose algorithms about supplying the intermediate channel assignment in order to avoid these demerits. This method will help other methods that use time slot assignment scheduling of CTA.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1485-1491
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• 2015

This paper introduces a new pilot assignment algorithm for uplink Massive multiple-input multiple-output (MIMO) systems. Since the conventional pilot assignment algorithm has the performance degradation compared to the optimal algorithm which performs the exhaustive search, we propose a new pilot assignment algorithm using Pre-determined Interference and Pre-determined Desired-term techniques. The proposed algorithm has the low complexity and guarantees negligible performance loss compared to the optimal algorithm. Simulation result verifies that the proposed algorithm achieves a large performance gain over the conventional algorithm.