• Transactions on Electrical and Electronic Materials
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• v.18 no.2
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• pp.111-118
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• 2017

The increased diversity of different types of energy sources requires moving towards smart distribution networks. This paper proposes a probabilistic DG (distributed generation) units planning model to determine technology type, capacity and location of DG units while simultaneously allocating ESS (energy storage systems) based on pre-determined capacities. This problem is studied in a wind integrated power system considering loads, prices and wind power generation uncertainties. A suitable method for DG unit planning will reduce costs and improve reliability concerns. Objective function is a cost function that minimizes DG investment and operational cost, purchased energy costs from upstream networks, the defined cost to reliability index, energy losses and the investment and degradation costs of ESS. Electrical load is a time variable and the model simulates a typical radial network successfully. The proposed model was solved using the DICOPT solver under GAMS optimization software.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.47-57
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• 2004

Industrial efforts for increased market sales have directed towards the development and implementation of on-line marketing systems under recent e-business environment. Internet-based shopping mall is one of the most popular system. A business process model for an intermediary type shopping mall using IDEF0 has been presented in this study. Specific efforts have been focused on defining and analyzing a diversity of business processes embedded in practical B2B and B2C mall system operations. We first briefly examined the considered system with IDEF0 design. We then defined fundamental business processes within shopping mall systems. Upon careful examination and analysis of them, a detailed business process model based on IDEF methodology has been designed. The results in this study may well form a conceptual framework for shopping mall development and operations.

• Toxicological Research
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• v.24 no.4
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• pp.235-243
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• 2008

While in some instances, loss of diversity results from acute toxicity (e.g. major pollution incidents), in most cases it results from long-term sub-lethal effects that alter the relative competitive ability and fitness of certain organisms. In such cases the sub-lethal effects will cause a physiological response in the organism that ultimately leads to community level changes. Very sensitive tools are now available to study sub-lethal responses at the molecular level. However, relating such laboratory measurements to ecological effects represents a substantial challenge that can only be met by investigation at all scales (molecular, individual organism and community level) with an appropriate group of organisms. Among the various in vertebrates which can be used as model organisms in such a way, the soil nematode, Caenorhabditis elegans appear to be a promising biological model to diagnose environmental quality. This paper reviews the current status of multilevel biomarkers in environmental toxicology, and C. elegans as promising organisms for this approach.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.10a
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• pp.128-132
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• 1998

This research is concerned with buffer management in a multi-cell FMS(Flexible Manufacturing System) with an AGVS(Automated Guided Vehicle System). To reduce blocking and starving caused by breakdowns, variablility in process times, and diversity of part routing, buffer is needed. Due to the high per unit buffer cost, which primarily consists of floor space and equipment cost, the total capacity of buffers in an FMS is very limited. Therefore, proper buffer management can provide a high system efficiency. This paper presents a buffer management model for a multi-cell FMS with an AGVS and a simulation study to compare the proposed model to a conventional buffer management model in a job shop FMS.

• Journal of Information Technology Applications and Management
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• v.13 no.4
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• pp.89-107
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• 2006

With the increased importance of groupware in organizations, groupware acceptance is regarded as an important outcome in the efforts of firms to leverage the potential of this information technology in their business activities and strategies. Despite significant investments in groupware, considerable diversity exists in how well firms have been able to implement groupware and leverage the business value of groupware. This study identifies important factors influencing user acceptance of groupware by extending TAM(Technology Acceptance Model) which includes perceived control, intrinsic motivation, and concentration as well as perceived ease of use and perceived usefulness from original TAM. The proposed model is tested in an organization among 104 employees using previous research measurements. According to the findings from the study, the usage intention of groupware can be explained by intrinsic motivation, perceived control, perceived ease of use, and Perceived usefulness. However, it fails to explain the effect of concentration on the intention.

• Journal of Information Technology Applications and Management
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• v.25 no.2
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• pp.73-90
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• 2018

Despite of increasing studies for product recommendation, the recommendation of product repurchase timing has not yet been studied actively. This study aims to propose deep neural network models usingsimple purchase history data to predict the repurchase timing of each customer and compare performances of the models from the perspective of prediction quality, including expected ROI of promotion, variability of precision and recall, and diversity of target selection for promotion. As an experiment result, a recurrent neural network (RNN) model showed higher promotion ROI and the smaller variability compared to MLP and other models. The proposed model can be used to develop a CRM system that can offer SMS or app-based promotionsto the customer at the right time. This model can also be used to increase sales for product repurchase businesses by balancing the level of ordersas well as inducing repurchases by customers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.8
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• pp.1659-1667
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• 1997

In DS-CDMA cellular systems, using the same frequency channel at the adjacent cells simultaneously makes soft handoff possible. In soft handoff, mobiles use multiple radio resources for the space diversity of signal in the overlapped region. The previous traffic models of hard handoff are not applicable to the system with soft handoff due to switching radio channels in that region. The handoff rate can be calculated by the mobility of mobiles, which is a function of the size and shape of a cell, and the speed and density of the mobiles. In this paper, we propose an analytical traffic model to study the soft handoff rate. We assume that the system uses a two-way handoff scheme for practical purposes, which connects only two cells to a mobile during soft handoff. We performed a computer simulation to confirm the accuracy of the proposed soft handoff model. The simulation results show good agreement with the analytical model.

• East Asian Economic Review
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• v.25 no.4
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• pp.403-424
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• 2021

AdaBoost tweaks the sample weight for each training set used in the iterative process, however, it is demonstrated that it provides more correlated errors as the boosting iteration proceeds if models' accuracy is high enough. Therefore, in this study, we propose a novel way to improve the performance of the existing AdaBoost algorithm by employing heterogeneous models and a stochastic twist. By employing the heterogeneous ensemble, it ensures different models that have a different initial assumption about the data are used to improve on diversity. Also, by using a stochastic algorithm with a decaying convergence rate, the model is designed to balance out the trade-off between model prediction performance and model convergence. The result showed that the stochastic algorithm with decaying convergence rate's did have a improving effect and outperformed other existing boosting techniques.

• The Journal of the Convergence on Culture Technology
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• v.10 no.4
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• pp.681-686
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• 2024

The film crews is a unique organization composed of members with expertise in each field and operated temporarily for a relatively short period of time. This study attempted to infer that the group characteristics and ability of the film crews to draw out the members' capabilities will affect the success or failure of the film, and to investigate their influence relationship. To this end, the research model was designed with diversity, cohesion, and information utilization as independent variables, and the artistry and box office performance of the film as dependent variables. As a result of the analysis, it was found that the diversity of the film crew affects both the artistry and box office performance, and the cohesion only affects the artistry. However, it was found that information utilization had no effect on film performance. It was confirmed that the diversity of the film crews was related to the film performance, and the cohesion had a limited effect. The results of this study provide implications that the design concept of the film crews based on diversity may be more important than process factors such as information utilization.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.2
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• pp.75-86
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• 2004

This study aims to figure out ecological characteristic of natural forests focusing on vegetation as a way of ecological renovation for the restoration of naturalness for golf courses that were constructed in the Country and to present vegetation models and appropriate tree species for the purpose. The study site is P golf club, which is located in Gapyong-gun, Kyeonggi Province. The site is within a forest where the grade from the natural ecology map is the first one and the level from the green index accounts for the eight, thus showing a typical environment for a golf course in terms of location. The location of the site explains a reason for restoration. The major substance of the study is to conduct ecological evaluation of vegetation structures around and inside the golf course and to present a vegetation model. In order to evaluate the ecological characteristics of the vegetation structures, the analysis of the study covered succession stages, multi-layer vegetation structures and species diversity. Plant communities that have high species diversity were selected for the vegetation model and proper density and species were proposed considering the number of species and individuals and distances between trees. The vegetation restoration model targets succession into an oak forest. Within a unit of 100 $m^2$, the recommended model include a tall-tree layer with 11 trees such as Quercus serrata and Quercus mongolica, a sub-tall-tree layer with 12 trees including Quercus mongolica, Quercus serrata, Prunus sargentii, Fraxinus rhynchophylla and Acer pseudo sieboldianum, a shrub layer with 32 trees from 16 species, and a grass layer with a cover rate of 45 %. The proposed vegetation restoration model needs to apply to : 1) damaged natural forests by the construction of golf courses; 2) boundaries between golf courses and surrounding forests; 3) buffer zones; 4) open spaces in between courses; and 5) areas between greens and tees where open spaces are available in a mass. In conclusion, one of the most important factors in presenting a vegetation model for the restoration of naturalness in the golf course and other damaged forests is to provide multi-layer vegetation structures that are composed of native species. As for the specific application for the site, it is recommended to manage the vegetation in such a way that the environment of the site can have a similar environment to the surrounding forest which is expected to succeed into an oaks-dominant one.