• Spatial Information Research
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• v.19 no.1
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• pp.107-116
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• 2011

Due to development of environment of wireless Internet, location based services on the basis of spatial data have been increased such as real time traffic information as well as CNS(Car Navigation System) to provide mobile user with route guidance to the destination. However, the current application adopting the file-based system has limitation of managing and storing the huge amount of spatial data. In order to supplement this challenge, research which is capable of managing large amounts of spatial data based on embedded database system is surely demanded. For this reason, this study aims to suggest the lossless compression technique by using the hybrid approach of BytePacking and Lempel-Ziv which can be applicable in DBMS so as to save a mass spatial data efficiently. We apply the proposed compression technique to actual the Seoul and Inchcon metropolitan area and compared the existing method with suggested one using the same data through analyzing the query processing duration until the reconstruction. As a result of comparison, we have come to the conclusion that suggested technique is far more performance on spatial data demanding high location accuracy than the previous techniques.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.1
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• pp.36-44
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• 2003

This paper proposes a Viterbi decoding scheme without trace-back operations to reduce the amount of memory storing the survivor path information, and to increase the decoding speed. The proposed decoding scheme is a modified register exchange scheme, and is verified by a simulation to give the same results as those of the conventional decoders. It is compared with the conventional decoding schemes such as the trace-back and the register exchange scheme. The memory size of the proposed scheme is reduced to 1/(5 x constraint length) of that of the register exchange scheme, and the throughput is doubled compared with that of the trace-back scheme. A decoder with a code rate of 2/3, a constraint length, K＝3 and a trace-back depth of 15 is designed using VHDL and implemented in an FPGA. It is also shown that the modified register exchange scheme can be applied to a block decoding scheme.

• Journal of the Korean Society for Railway
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• v.16 no.4
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• pp.241-245
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• 2013

In the case of the existing train control system, the driver monitors the condition of the vehicle through a composite controller device that displays various information on a screen in the vehicle. However, when problems arise such as car trouble, it is difficult for the drivers to take action immediately. In addition, maintenance personnel have to manually save data one by one after storing the vehicle to analyze control information of the main devices such as the brake controller and auxiliary power. To improve these points, a system that sends and receives all information in real time should be established by installing a sensor communication network and a surveillance system. This study attempts to improve the safety and maintenance of rail vehicles by suggesting a standardized method for train control and surveillance system.

• Journal of the Korea Society for Simulation
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• v.26 no.2
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• pp.19-29
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• 2017

System Entity Structure/Model Base (SES/MB) enhances organizing model families and storing and reusing model components in the multifaceted system modeling. However, the real world can be described not only an individual system but also a collection of those systems, which is called system of systems (SoS). Because SES/MB has a limitation to simulate the SoS using HLA/RTI, an extended framework is required to simulate it. Therefore, this paper proposes System of Systems Entity Structure/Federate Base (SoSES/FB) for simulation in a distributed environment (HLA/RTI). The proposed method provides the library of federates (FB) and System of System Entity Structure (SoSES) formalism, which represents structural knowledge of a collection of simulators. It also provides a methodology for the development process of distributed simulation. The paper introduces the anti-missile defense simulation using the proposed SoSES/FB.

• Journal of the Korea Computer Graphics Society
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• v.6 no.4
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• pp.35-42
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• 2000

3D texture mapping generates highly natural visual effects in which objects appear carved from lumps of materials rather than laminated with thin sheets as in 2D texture mapping. Storing 3D texture images in a table for fast mapping computations, instead of evaluating procedures on the fly, however, has been considered impractical due to the extremely high memory requirement. Recently, a practical real-time 3D texture mapping technique was proposed in [11], where they attempt to resolve the potential texture memory problem by compressing 3D textures using a wavelet-based encoding method. In this paper, we consider two other encoding schemes that could also be applied to the compression-based 3D texture mapping. In particular, we extend the vector quantization and FXT1 for 3D texture compression, and compare their performance with the wavelet-based encoding scheme.

• The KIPS Transactions:PartD
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• v.13D no.5 s.108
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• pp.651-660
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• 2006

Algorithms for mining association rules based on the Apriori algorithm use the hash tree data structure for storing and counting supports of the candidate frequent itemsets and the most part of the execution time is consumed for searching in the hash tree. The DHP(Direct Hashing and Pruning) algorithm makes efforts to reduce the number of the candidate frequent itemsets to save searching time in the hash tree. For this purpose, the DHP algorithm does preparative simple counting supports of the candidate frequent itemsets. At this time, the DHP algorithm uses the direct hash table to reduce the overhead of the preparative counting supports. This paper proposes and evaluates an efficient hashing mechanism for the direct hash table $H_2$ which is for pruning in phase 2 and the hash tree $C_k$, which is for counting supports of the candidate frequent itemsets in all phases. The results showed that the performance improvement due to the proposed hashing mechanism was 82.2% on the maximum and 18.5% on the average compared to the conventional method using a simple mod operation.

• The Korean Journal of Nuclear Medicine
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• v.24 no.1
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• pp.101-107
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• 1990

To develop $^{131}I-labelled$ m-iodobeneylguanidine $(^{131}I-MIBG)$, various experiments such as synthesis of MIBG, establishment of labelling conditions, determination of radiochemical purity, and examination of stability were carried out. 1) m-Iodobenzylguanidine (MIBG) sulfate was synthesized with a total yield of 62.4% by the condensation of m-iodobenzylamine hydrochloride with cyanamide via MIBG bicarbonate. Its physical properties, IR, $^1H-NMR$, and elemental analysis data were nearly identical to those of literature. 2) Freeze-dried or vacuum-dried kit vials were prepared from the mixture so as to contain MIBG (2 mg), ascorbic acid (10 mg), copper (II) sulfate (0.14 mg), and tin (II) sulfate (0.5 mg) per vial. Copper ( I ) catalyzed radioiodination of MIBG was carried out using kit vials and 0.01 M $H_2SO_4$ as solvent at $100^{\circ}C$ for 30 min under nitrogen atmosphere (optimal conditions). Labelling yield was 98% and radiochemical purity was 99.5%, respectively. 3) Solid-phase radioiodination of MIBG was carried out at $155^{\circ}C$ for 30 min using the prepared vials to contain MIBG (2 mg) and ammonium sulfate (10 mg). Duplicate reactions under the same conditions showed labelling yield of 95% and radiochemical purity of 99.5%. 4) $^{131}I-MIBG$ prepared either by catalytic or by solid-phase exchange method showed radio-chemical purity of 99% even after 3 days storing at room temperature.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.1
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• pp.55-60
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• 2013

Compound bows use levering systems consisting of cables and cam pulleys to bend limbs that are much stiffer than those of recurve bows, thus storing more energy while requiring less force for the archer to hold the bow at a fully drawn position. Many patents have thus far been proposed to improve the efficiency and performance of compound bows through empirical methods, whereas only a few analytical methods have been proposed. In this light, this paper presents a method for the kinematic analysis of levering systems in compound bows so that a designer can easily predict the effects of changes in the cam profiles and limb materials.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.1
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• pp.68-76
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• 1999

The intuitive understanding of the dynamic pattern generation in asymmetric networks may be useful for developing models of dynamic information processing. In this paper, dynamic behavior of the ring connection neural network in which each neuron is only to its nearest neurons with binary synaptic weights of ±1, has been inconnected vestigated Simulation results show that dynamic behavior of the network can be classified into only three categories: fixed points, limit cycles with basin and limit cycles with no basin. Furthermore, the number and the type of limit cycles generated by the networks have been derived through analytical method. The sufficient conditions for a state vector of n-neuron network to produce a limit cycle of n- or 2n-period are also given The results show that the estimated number of limit cycle is an exponential function of n. On the basis of this study, cyclic connection neural network may be capable of storing a large number of dynamic information.

• Journal of KIISE:Software and Applications
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• v.30 no.11
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• pp.1054-1061
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• 2003

Q-Learning, a representative algorithm of reinforcement learning, experiences repeatedly until estimation values about all state-action pairs of state space converge and achieve optimal policies. When the state space is high dimensional or continuous, complex reinforcement learning tasks involve very large state space and suffer from storing all individual state values in a single table. We introduce Q-Map that is new function approximation method to get classified policies. As an agent learns on-line, Q-Map groups states of similar situations and adapts to new experiences repeatedly. State-action pairs necessary for fine control are treated in the form of rule. As a result of experiment in maze environment and mountain car problem, we can achieve classified knowledge and extract easily rules from Q-Map