• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.211-213
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• 1999

This paper describes a new method for source current optimization of the electromagnetic devices. In a conventional method of current distribution optimization using design sensitivity based on a finite element method, position and width of coils are generally optimized under condition that shape of those is given. they cannot find the global minimum because the number of coils is pre-determined. To avoid this local minimum, source current region which is discretized uniformly is considered as design parameter. This discretized regions have zero or one current value during the optimization process. The proposed method is applied to magnetic resonance imaging(MRI) magnet.

• ETRI Journal
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• 제29권5호
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• pp.655-666
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• 2007

There are nodes and edges in a topological map. Node data has been used as a main source of information for the localization of mobile robots. In contrast, edge data is regarded as a minor source of information, and it has been used in an intuitive and heuristic way. However, edge data also can be used as a good source of information and provide a way to use edge data efficiently. For that purpose, we define a data format which describes the shape of an edge. This format is called local generalized Voronoi graph's angle (LGA). However, the LGA is constituted of too many samples; therefore, real time localization cannot be performed. To reduce the number of samples, we propose a compression method which utilizes wavelet transformation. This method abstracts the LGA by key factors using far fewer samples than the LGA. Experiments show that the LGA accurately describes the shape of the edges and that the key factors preserve most information of the LGA while reducing the number of samples.

• Wind and Structures
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• 제3권1호
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• pp.11-21
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• 2000

This paper presents results of modeling of the passive contaminant diffusion from a continuous line finite-size source located on the underlying surface of a neutral near-ground atmospheric layer obtained by using the non-local two-parameteric turbulence model and the transport equation of mean concentration. In the proposed diffusion model the turbulent diffusion coefficient changes not only with the vertical coordinate but also with the distance downstream from the source according to the experimental data. The results of the modeling reproduce structural features of the concentration field.

• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.280-292
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• 2021

Enterprise Resource Planning (ERP) is a software that manages and automate the internal processes of an organization. Process speed and quality can be increased, and cost reduced by process automation. Odoo is an open source ERP platform including more than 15000 apps. ERP systems such as Odoo are all-in-one management systems. Odoo can be suitable for small and medium organizations, but duo to efficiency limitations, Odoo is not suitable for the large ones. Furthermore, Odoo can be implemented on both local or public servers in which each has some advantages and disadvantages such as; the speed of internet, synced data or anywhere access. In many cases, there is a persistent need to have more than one synchronized Odoo instance in several physical places. We modified Odoo to support this kind of requirements and improve its efficiency by replacing its standard database with a distributed one, namely CockroachDB.

• ETRI Journal
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• 제41권5호
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• pp.658-669
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• 2019

For dual-channel time-frequency (TF) overlapped signals with low sparsity in underdetermined blind source separation (UBSS), this paper proposes an effective method based on interval probability to estimate and expand the types of mixing matrices. First, the detection of TF single-source points (TF-SSP) is used to improve the TF sparsity of each source. For more distinguishability, as the ratios of the coefficients from different columns of the mixing matrix are close, a local peak-detection mechanism based on interval probability (LPIP) is proposed. LPIP utilizes uniform subintervals to optimize and classify the TF coefficient ratios of the detected TF-SSP effectively in the case of a high level of TF overlap among sources and reduces the TF interference points and redundant signal features greatly to enhance the estimation accuracy. The simulation results show that under both noiseless and noisy cases, the proposed method performs better than the selected mainstream traditional methods, has good robustness, and has low algorithm complexity.

• 한국환경과학회지
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• 제16권3호
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• pp.299-310
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• 2007

It will be necessary to make proper management plans to preserve the air quality in good level for the public. In order to make these plans, source information and detail emission inventories of the city and near industrial areas should be given. However, lack of the source measurements data makes us more difficult to complete the source inventory. VOC source Inventory could be utilized for the feasibility study to estimate the contribution of VOC sources presenting to the receptor such as residential area. It may give policy maker an idea how to control the air quality, and improve their social environment in the area. This study shows data that measured VOCs concentrations from the local industrial areas in Jeonju during from May 2005 to January 2006. The samples were collected from the near sources in 7 major factories in the industrial park as well as 5 general sources in near city Jeonju area to elucidate the abundances of speciated VOCs and their spacial and temporal distributions depending on source bases. Industrial sources are as follows; chemical, food, paper, wood, metal, non-metal (glass), and painting (coating) industries. The 5 general sources are sampled from tunnel, gasoline gas station, dry cleaning shop, printing (copy) shop, and road pavement working place in urban area. To understand the near source effect at receptor, samples from the 2 receptor sites (one is at center of the industrial complex and the other site is at distance residential area downwind from the center) were collected and analyzed for the comparison to source concentration. The mass contributions of the speciated VOC to total mass of VOCs measured from the different sources and ambient (2 receptors) were presented and discussed.

• 가족자원경영과 정책
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• 제16권1호
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• pp.67-83
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• 2012

Baby boomers are often defined by their support of their parents and their devotion to their children's educational success by providing financial and emotional aids. Now, 7.12 million baby boomers in South Korea are retiring, or are about to retire, without any retirement plans. Similar to financial stability, health, and leisure life, social capital is another important element in the quality life after retirement. This is because social capital can function as a potential resource network. Social capital is a source that provides money, information, goods, services, emotional aids, social relational opportunities etc. In the past, family and community provided social capital for the aged. However, the baby boomer generation cannot expect the same. The baby boomers have the task of creating new social capital that can assure their quality of life. Therefore, this study examines cohort characteristics of the baby boomer generation and, based on the examination, seeks an alternative for social capital. The results are as follows: First, social capital from the local community can be an alternative source of caring for the baby boomers in old age. Second, among the social capital of the local community, elderly care supported by a family friendly community is proposed. In addition, baby boomers must become the primary social capital that contributes to a mature civil society rather than a beneficiary of welfare for the aged.

• 한국통신학회논문지
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• 제32권9B호
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• pp.589-597
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• 2007

In this paper, a WDM metro ring consisting of access nodes with $FT-FR^n$ (Fixed Transmitter - n Fixed Receivers) is considered. A trade-off exists between node throughput and transmission fairness because the access nodes share wavelength channels. In order to eliminate the transmission unfairness and to increase throughput, the p-persistent medium access control (MAC) protocol is proposed: each node uses an empty optical slot to transmit a packet and make it available with the extraction of a transferred packet at the source access node, called source-stripping. The local empty slot can be used to transfer a head-of-line packet in the local buffer with probability p or it is used for the next downstream nodes with 1-p. The proposed MAC protocol provides better node throughput than the non-persistent protocol and exhibits better fairness index than the 1-persistent protocol in WDM ring networks. In addition, numerical analysis shows that the proposed MAC protocol maximizes the node throughput under uniform traffic conditions. For more detailed results, we use the network simulation under Poisson and self-similar traffic. Furthermore, unpredictable traffic constructed by the combination of the former and the latter is also considered. The reasonable probability of the p-persistent protocol for a given architecture can be determined through simulation.

• 전기전자학회논문지
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• 제22권3호
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• pp.558-564
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• 2018

In distributed estimation where each node can collect only partial information on the parameter of interest without communication between nodes and quantize it before transmission to a fusion node which conducts estimation of the parameter, we consider a novel quantization technique employed at local nodes. It should be noted that the performance can be greatly improved if each node can transmit its measurement to one designated node (namely, head node) which can quantize its estimate using the total rate available in the system. For this case, the best strategy at the head node would be simply to partition the parameter space using the generalized Lloyd algorithm, producing the global codewords, one of which is closest to the estimate is transmitted to a fusion node. In this paper, we propose an iterative design algorithm that seeks to efficiently assign the codewords into each of quantization partitions at nodes so as to achieve the performance close to that of the system with the head node. We show through extensive experiments that the proposed algorithm offers a performance improvement in rate-distortion perspective as compared with previous novel techniques.

• 한국대기환경학회지
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• 제16권6호
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• pp.585-594
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• 2000

Through an application of Micrometerorological methods, we conducted measurements of Hg fluxes from Nan-Ji-Do which is well known as one of the major local areal sources in Seoul metropolitan area during Match/April of 2000. In the course of our study, we determined the concentration gradients of total gaseous Hg(between 20 and 2000 cm heights) and combined these data with Micrometerorological components to derive is fluxes. It turned out that emission from and dry deposition to soil surfaces occurred at the ratio of 72:27 from a total of 271 hourly measurements. The validity of measured concentration gradients( or resulting fluxes) was evaluated in terms of percent gradient. Accordingly, about more than 95% of gradient data derived were statistically significant. The mean fluxes of Hg across soil-air interface, when computed using the concentrations gradients and relevant parameters, were found at 253(during emission) and -846ng/$m^2$/h(during dry deposition) The occurrences of abnormalously high exchange rates appear to be the combined effects of enormously high gradient values and high transfer coefficients. While the emissions of Hg occurred constantly during the whole study periods, the occurrences of dry deposition events were observed most intensively during very limited time periods(3/29 and 4/3). The results of our study cleary indicated that the studied area is a strong local areal source, while exhibiting great potential as a major sink simultaneously.