• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.251-254
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• 2003

In this paper, we develop an effective method for estimating and predicting interference power strength using the IMM(Interacting Multiple Model) algorithm. Based on the proposed interference prediction algorithm, we adjust transmission power of mobile terminals to maintain a certain level of target signal - to - interference- plus -noise- ratio ( SINR ) at the base station. Results of numerical experiments are presented to show a performance profile of the proposed algorithm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.11
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• pp.15-22
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• 2008

The cdma2000 1xEV-DO system controls the data rates of mobile terminals based on a binary overload indicator from the base station and a simple probabilistic model. However, this control scheme has difficulty in predicting the future behavior of mobile terminals due to a probabilistic uncertainty and has no reliable means of suppressing the traffic overload, which may result in performance degradation of CDMA systems that have interference-limited capacity. This Paper proposes a new traffic control scheme that controls the data rates of mobile terminals effectively by predicting the future traffic load and adjusting the forward-link control channel. The proposed scheme is analyzed by modeling it as a multi-dimensional Markov process and compared with conventional schemes. The numerical results show that the maximum cell throughput of the proposed scheme is much higher than those of the conventional schemes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.8
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• pp.1843-1850
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• 2004

If the location information of a great number of cars kept for business with telematics terminals is acquired and managed efficiently, this information forms the foundation for controlling cars and traffic flows. The studies on the pure spatial indices have focused on the efficient retrievals. However, the acquisition and management of the terminal location of moving objects are more important than the efficiency of the query processing in the moving object databases. Therefore, it will be need to adopt parallel processing system for the moving object databases which should maintain the object's current location as precise as possible. This paper proposes a location management system using CDMA communications of telematics terminals. More precisely, we propose a architecture of spatial indexing mobile objects using multiple processors, and also newly propose a method of splitting buckets using the properties of moving objects in order to minimize the number of database updates. We also propose a acquisition method for gathering the location information of moving objects and passing the information of the bucket extents in order to reduce the amount of passed messages between processors.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2000.11a
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• pp.463-470
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• 2000

In this paper, we describe a wireless MAC protocol named APRMA(Abitrary Period Reservation Multiple Access), which is capable of supporting the ABR type data service and maximizing channel utilization. In original PRMA protocol, data terminals with random data packets cannot reserve slot. That is, slot reservation is applicable to the. time constraint voice packet exclusively. But the reservation scheme have to be performed for loss sensitive data packet, so data packets can get their quality of service. The aspects of service, if fixed bandwidth is allocated to data terminals, time constraint voice packets may have a low efficiency So in this study, the terminal which wants to request for ABR type service, acquires a minimum bandwidth from system for the first time. If the system have extra available bandwidth, ABR terminals would acquire additional bandwidth slot by slot. As a result, APRMA protocol can support the data service with loss sensitivity and maintain their channel utilization highly. Also high Priority services like voice can be satisfied with their QoS by APRMA.

• Journal of Korea Port Economic Association
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• v.36 no.4
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• pp.75-92
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• 2020

Currently, shipping and port industries are mainly concerned with securing a competitive advantage through scale expansion. Reflecting this trend, domestic ports and container terminals also emphasize efficiency through dock integration. This study identified factors that facilitate cooperation between container terminal operators, as the smallest unit of port operation, and analyzed their effects. These factors included sharing of resources, clarity of purpose, mutual trust, and influence of government policies. In addition, factors related to effectiveness included operational effectiveness of the terminal, improved service to shippers and shipping companies, and bargaining power with the government. The empirical analysis revealed that, among the factors that facilitate cooperation, sharing and purpose affected operational effectiveness, while sharing of resources affected service improvement of shippers and shipping companies. Finally, policy factors affected port bargaining power.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2098-2117
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• 2012

This paper jointly investigates the bandwidth allocation, transmission strategy and relay positions for two-way transmission aware cellular networks with network coding (NC). Our goal is to minimize the transmission power of mobile terminals (MTs). Consider a cellular system, where multiple MTs exchange information with their common base station, firstly, we propose an efficient bandwidth allocation method and then give a transmission strategy for each MT to determine whether to use relay stations (RSs) for its two-way transmission with the BS or not. To further improve the system performance, the optimal positions of RSs are also jointly discussed. A GA-based algorithm is presented to obtain the optimum positions for RSs. Besides, the impacts of frequency reuse on MT's transmission power and system spectral efficiency (SE) under different number of relays are also discussed in our work. Numerical results show that the proposed NC aware scheme can extend MTs' battery life at least 6% more than traditional method.

• The Korean Journal of Zoology
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• v.26 no.2
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• pp.107-123
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• 1983

The globus pallidus of normal cats were prepared for electron microscopic study following perfusion with a mixture of 1% paraformaldehyde and 1% glutaraldehyde solution. Neurons of two size categories were identified in 1 $\\mu$m araldite sections and their ultrastructural characteristics were studied in adjacent thin section. 1. Large neurons ($30 \\mum \\times 45 \\mum$ in diameter) had extensive areas of rough surfaced endoplasmic reticulm, abundant perinuclear Golgi complex, numerous mitochondria and lipofusin granule, and had a large spherical nucleus with shallow indentation of nuclear manbrane. Small neurons ($17 \\mum \\times 27 \\mum$ in diameter) had poorly rough surfaced endoplasmic reticulum, moderate number of mitochondria and randomly distributed Golgi complex. The nuclear envelope of this cell frequently showed multiple deep invagination. 2. Three types of axo-somatic synapses were identified on the basis of the size and shape of vesicle in the axon terminal and the symmetrical or asymmetrical thickening at the synaptic site. Type I synaptic terminal shows an even distribution of round and oval synaptic vesicles, and has a symmetrical synaptic thickening. Type II axon terminals reveal mostly round and pleomorphic vesicles and a few vesicles were localized near the presynaptic membrane in pale axoplasm and its synaptic thickening were symmetric. Type III axon terminals contain round vesicles, which were aggregated in the axoplasm, and has a asymmetrical synaptic thickening. 3. The majority of axo-somatic contact with the large and small neurons were type I, and type II and III synapes were rare.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.3
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• pp.248-257
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• 2011

Cross docking is a logistics management concept in which items delivered to a terminal by inbound trucks are immediately sorted out, routed and loaded into outbound trucks for delivery to customers. Two main advantages by introducing a cross docking terminal are to consolidate multiple smaller shipment into full truck load and remove storage and order picking processes to save up logistics costs related to warehousing and transportation costs. This research considers the scheduling problem of trucks in the cross docking terminals with multi-door in an inbound and outbound dock, respectively. The trucks sequentially deal with the storage process at the one of inbound doors and the shipping process at the one of the outbound doors. A mathematical model for an optimal solution is derived, and genetic algorithms with two different chromosome representations are proposed. To verify performance of the GA algorithms, we compare the solutions of GAs with the optimal solutions and the best solution using randomly generated several examples.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.345-351
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• 2010

It has been growing interests that convergence services of broadcasting and telecommunication services such as DMB 2.0 and Mobile IPTV etc. Unicast type is difficult to service broadcasting due to limits of capacity and poor receiving environments, WiBro supports broadcast service with MBS. MBS is transmission method that base stations belong to same the MBS zone transmit the all users who request broadcasting service. Terminals are received resources from all base station in the MBS zone and SINR can be improved because of macro diversity. If terminals are located at edge of the MBS zone, complement algorithm are needed beacause received SINR is very low. In this paper, MIMO STBC, Relay and FFR are introduced to improve the throughputs using high MCS. The basic simulation environment is assumed to be SISO. Transparent relay and FFR applicable on MBS are divided by SISO and MIMO STBC environment and evaluate the performance.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.4
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• pp.141-157
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• 2004

In this paper, we consider broadband satellite systems using MF-TDMA(Multi-Frequency Time Division Multiple Access) scheme. First, we analyze return link, superframe structure, and QoS( Quality of Service) parameters in broadband satellite systems, and mathematically formulate the QoS-based optimal timeslot allocation problem as a nonlinear integer programming problem for broadband satellite systems with clear-sky and rain-fade satellite terminals, and multiple data classes. Next, we modify the proposed problem to solve it within in a fast time, and suggest the QoS-based optimal timeslot allocation scheme. Extensive simulation results show that the proposed scheme finds an optimal solution or a near optimal solution within 5ms at Pentium IV PC.