• International journal of advanced smart convergence
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• v.7 no.4
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• pp.10-18
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• 2018

For the information services supporting requests of data items from a great number of mobile clients, wireless data broadcasting is an effective way because it can accommodate any number of clients. In the wireless data broadcasting, various air indexing schemes and data scheduling schemes have been developed in order to enable the clients to access their desired data items efficiently. The broadcasting system needs a method to simulate newly designed air indexing and scheduling schemes of the system, and to evaluate the performance parameters of the schemes. In this paper, we design an expandable and efficient simulation framework for the wireless data broadcasting based on the partition of data ID space. The framework can adopt regular and irregular space partition and evaluate various performance parameters of the broadcasting system. We implement a testbed of the broadcasting system using the framework, that adopts IIP, GDI and EXP as its air indexing schemes. We simulate the system using the testbed and evaluate the performance parameters of the system. Thus, we show the efficiency and expandability of the designed and implemented framework.

• Journal of the Korean Association of Geographic Information Studies
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• v.4 no.1
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• pp.47-56
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• 2001

Present address system in korea was originally applied as a lot number system for the purpose of collecting taxes since 1910's, which has been changed irregularly by development of the urban areas. This unreasonable address system has disadvantaged the social welfare and the industrial structure, such as visiting, communication, delivery, sightseeing, marketing, transportation, etc. Therefore the new system, which would be rational and scientific, has been deeply demanded for the better services of spatial information and administrative efficiency of government. Korean government has launched the new address project as part of strengthening measures for national competitiveness since 1996. This paper would discuss the grant scheme of road name and building number in Cheongju city and evaluate the construction process of the new address management system.

• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.183-190
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• 1985

The glucose nonfermenting gram-negative bacilli encountered about 10% of all gram-negative bacilli isolated from clinical material. Therefore, a rapid and correct identification of glucose nonfermenting gram-negative bacilli is impostent for a better management of infectious disease. There are many conventional systems for the Identification of glucose nonfermenting gram-negative bacilli but most of them have problems and difficulties. Commercial Kit Systems exist and they are too expensive for dally use 10 Korea because of high cost. Based on 12 selected tests we propose a new code system, MCRCODE-N for rapid and 10-expensive identification of glucose nonfermenting gram-negative bacilli. The selective 12 tests are oxidase, glucose oxidation motility, urease, DNase arginine dehydrolase, nitrate reduction, gelatin Liquefaction, esculin hydrolysis, mannitol oxidation, maltose oxidation, Lactose oxidation. The 12 tests are divided 4 group and then each group has 3 tests. The result of each group is expressed by the number as below. The positive test is given by specific number (1st test = 1, 2nd test = 2, 3rd test = 4), while any negative result is 0. Each 3 numbers of one group are added and make number of 1 digit. Four digit number is refered to the code book of MCRCODE-N system or MCRCODE system using computer (Apple-II model) created by authors. This MCRCODE-N system is suitable ones for our use 10 Korea. We propose the MCRCODEN-N system for clinical use.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.474-486
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• 2015

This paper proposes a multi-objective optimal placement method of Phasor Measurement Units (PMUs) in large electric transmission systems. It is proposed for minimizing the number of PMUs for complete system observability and maximizing measurement redundancy of the buses, simultaneously. The measurement redundancy of the bus indicates that number of times a bus is able to monitor more than once by PMUs set. A high level of measurement redundancy can maximize the system observability and it is required for a reliable power system state estimation. Therefore, simultaneous optimizations of the two conflicting objectives are performed using a binary coded firefly algorithm. The complete observability of the power system is first prepared and then, single line loss contingency condition is added to the main model. The practical measurement limitation of PMUs is also considered. The efficiency of the proposed method is validated on IEEE 14, 30, 57 and 118 bus test systems and a real and large- scale Polish 2383 bus system. The valuable approach of firefly algorithm is demonstrated in finding the optimal number of PMUs and their locations by comparing its performance with earlier works.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1492-1501
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• 2015

This paper analyzes the effect of voltage sag on distribution systems due to the connection of Electric Vehicles (EVs). In order to study the impact of the voltage sag on the power system, two scenarios have been selected in this paper. The distribution system and EVs are modeled using the Electro Magnetic Transients Program (EMTP). The numbers of EVs are predicted based on the number of vehicles in distribution system of Seoul. In addition, the number of EVs is set up using real-time traffic in Seoul to simulate Scenario I and II. The simulation results show that voltage sag can occur if the distribution system has more than 30% of the total number of vehicles.

• Korean System Dynamics Review
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• v.16 no.4
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• pp.129-153
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• 2015

Mandatory shutdown policy of the juvenile protection act was enforced in December 2011 to prevent game addiction of the youth. However, the size of game market in Korea seems to be reduced significantly after implementation of the shutdown policy. The purpose of this study is to investigate the impact of current government regulations on Korean online game market. Based on empirical evidences and results from the related literature, we developed several causal loop diagrams(CLD) and system dynamics models. The CLD include sub-diagrams of innovation processes, user commitments, and operational costs. We conducted simulation analyses under various policy scenarios, adopting Normalized Unit Modelling By Elementary Relationship(NUMBER). Our results show that first, the impact of time regulation on the number of users is greater than the impact of content regulation. Second, the quality of domestic online game appears more elastic to regulations than the quality of foreign online game. The results of this study suggest that the deregulation in Korean online game market can narrow the gap in market outcomes between domestic and foreign online games. Some recommendations for future study are suggested.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.8
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• pp.671-677
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• 2017

A new INS/Vision integrated navigation system by using multi-vision sensors is addressed in this paper. When the total number of landmark measured by the vision sensor is smaller than the allowable number, there is possibility that the navigation filter can diverge. To prevent this problem, multi-vision concept is applied to expend the field of view so that reliable number of landmarks are always guaranteed. In this work, the orientation of camera installed are 0, 120, and -120degree with respect to the body frame to improve the observability. Finally, the proposed technique is verified by using numerical simulation.

• Convergence Security Journal
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• v.6 no.2
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• pp.81-89
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• 2006

System level diagnosis algorithms use the properties of t-diagnosable system where the maximum number of the faults does not exceed t. The existing diagnosis algorithms have limit when dealing with large fault sets in large multiprocessor systems. Somani and Peleg proposed t/k-diagnosable system to diagnose more faults than t (dimension) by allowing upper bounded few number of units to be diagnosed incorrectly. In this paper, we propose hypercube diagnosis algorithm using t/k-diagnosable system. When the number of faults exceeds t, we allow k faults to be diagnosed incorrectly. Simulation shows that the performance of the proposed algorithm is better than Feng's HADA algorithm. The proposed algorithm also gives similar performance compared to HYP-DIAG algorithm.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.2
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• pp.191-200
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• 2007

We propose the QoS (Quality of Service) assurance model for AMR (Adaptive MultiRate) voice users considering the capacity and service quality jointly in downlink WCDMA system. For this purpose, we introduce a new system performance measure and the number-based AMR mode allocation scheme. The proposed number-based AMR mode allocation can be operated only with the information of total number of ongoing users. Therefore, it can be more simply implemented than the existing power-based allocation. The proposed system performance measure considers the stochastic variations of AMR modes of ongoing users and can be analytically obtained using CTMC (Continuous Time Markov Chain) modeling. In order to validate the proposed analytical model, a discrete event-based simulation model is also developed. The performance measure obtained from the analytical model is in agreement with the simulation results and is expected to be useful for parameter optimization.

• Journal of the military operations research society of Korea
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• v.25 no.2
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• pp.15-30
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• 1999

A number of combat simulation models are scattered and the analytic solution approaches have experienced very difficult computational efforts. Today´s computer communication technology let people to do many unrealistic things possible and the use of those technologies is becoming increasingly prevalent throughout the military operation. Both DIS and ADS are welled defined computer aided military simulations. This study discusses a simulation of stochastic combat network modeling through Internet space. We have developed two separate simulation models, one for clients and another for server, and validated for conducting studies with these models. The object-oriented design was necessary to define the system entities and their relationship, to partition functionality into system entities, and to transform functional metrics into realizations derived from system component behaviors. Heterogeneous forces for each side are assumed at any battle node. The time trajectories for mean number of survivors and combat history at each node, some important combat measures, and relative difference computations between models were made. We observe and may conclude that the differences exit and some of these are significant based on a limited number of experiments.