• Journal of the Korean Operations Research and Management Science Society
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• v.10 no.2
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• pp.1-14
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• 1985

This problem of product selection and princing are considered in congested and uncongested markets. In a congested market, such as a computer service market, product quality (the level of congestion) is partly a function of the amount of usage, which in turn depands on user choice. In an uncongested market, product qualities are set solely by providers. A model of quality and capacity variation is developed using a state equation description to represent user optimizing behavior. The model is used to study the problem of scarce resources among competing user demands through quality-dependent pricing.

• Journal of Communications and Networks
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• v.18 no.6
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• pp.892-901
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• 2016

In the multi-user multiple-input multiple-output (MIMO) system, orthogonal random beamforming (ORBF) scheme is proposed to serve multiple users simultaneously in order to achieve the multi-user diversity gain. The opportunistic space-division multiple access system (OSDMA-S) scheme performs multiple weighting matrices during the training phase and chooses the best weighting matrix to be used to broadcast data during the transmitting phase. The OSDMA-S scheme works better than the original ORBF by decreasing the inter-user interference during the transmitting phase. To save more time in the training phase, a partly random multiple weighting matrices selection scheme is proposed in this paper. In our proposed scheme, the Base Station does not need to use several unitary matrices to broadcast pilot symbol. Actually, only one broadcasting operation is needed. Each subscriber generates several virtual equivalent channels with a set of pre-saved unitary matrices and the channel status information gained from the broadcasting operation. The signal-to-interference and noise ratio (SINR) of each beam in each virtual equivalent channel is calculated and fed back to the base station for the weighting matrix selection and multi-user scheduling. According to the theoretical analysis, the proposed scheme relatively expands the transmitting phase and reduces the interactive complexity between the Base Station and subscribers. The asymptotic analysis and the simulation results show that the proposed scheme improves the throughput performance of the multi-user MIMO system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.7
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• pp.1802-1814
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• 2012

In order to guide users to select the most optimal access network in heterogeneous wireless networks, a network selection algorithm is proposed which is designed based on multi-objective discrete particle swarm optimization (Multi-Objective Discrete Particle Swarm Optimization, MODPSO). The proposed algorithm keeps fast convergence speed and strong adaptability features of the particle swarm optimization. In addition, it updates an elite set to achieve multi-objective decision-making. Meanwhile, a mutation operator is adopted to make the algorithm converge to the global optimal. Simulation results show that compared to the single-objective algorithm, the proposed algorithm can obtain the optimal combination performance and take into account both the network state and the user preferences.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.11-18
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• 2018

To interact with a virtual object in immersive virtual environment, the target object should be selected quickly and accurately. Conventional 3D ray casting method using a direction of user's hand or head allows the user to select an object quickly. However, accuracy problem occurs when selecting an object using conventional methods among occlusion of objects. In this paper, we propose a region of interest based selection method that enables to select an object among occlusion of objects using a combination of gaze tracking and hand gesture recognition. When a user looks at a group of occlusion of objects, the proposed method recognizes user's gaze input, and then region of interest is set by gaze input. If the user wants to select an object among them, the user gives an activation hand gesture. Then, the proposed system relocates and visualizes all objects on a virtual active window. The user can select an object by a selecting hand gesture. Our experiment verified that the user can select an object correctly and accurately.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.1
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• pp.57-61
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• 1984

This paper deals with the selection of minimal test instruction set for microprocessor data processing test. This test method is based on a function description of the instructions which are obtained from the data given by the user's manual. Selecting procedure is done in 3 steps: 1) a test execution graphs are represented on the instructions which are grouped functionally, 2) the essential graphs, the eliminable graphs, the eliminable graphs, and the eligible graphs are built, 3) optimal test instruction set from the essential graphs and the eligible graphs is defined. In the case of INTEL 8048, 50 test instructions can be selected optimally from 8048 instruction repertories (96 instructions)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1597-1601
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• 2013

Multiple antenna technique is attracting attention as a core technology for next-generation mobile communication systems to accommodate explosively increasing mobile data traffic. Especially, recent researches focus on multi-user multiple input multiple output (MU-MIMO) system where base stations are equipped with several tens of transmit antennas and transmit data to multiple terminals (users) simultaneously. To enhance the performance of MU-MIMO systems, we, in this paper, propose an adaptive user selection algorithm which adaptively selects a user set according to varying channel states. According to Monte-Carlo based computer simulations, the performance of proposed scheme is significantly improved compared to the conventional scheme without user selection and approaches that of exhaustive search-based optimal scheme. On the other hand, the proposed scheme can reduce the computational complexity to $K/(2^K-1)$ compared to the optimal scheme where K denotes the number of total users.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.891-892
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• 2016

Recent research has become a smart home for operating the joining operation of the relationships between the device progress. However, Existing systems, there is a problem that the efficiency of the work can be degrade by the interference occurs when the operation of the other device, and triggered if the device is operating. In this paper, we designed a priority automatically set algorithm according to a user selection device to solve this problem. The user selects the device used by the application and by comparing between devices, select whether or not to set the priority of the tasks in. This allows the user can configure the working environment of only the desired device, and less chance of interference from other devices that are not selected during the work in progress can expect a more efficient productivity.

• Journal of Contemporary Eastern Asia
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• v.15 no.1
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• pp.78-97
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• 2016

Living labs are an increasingly popular methodology to enhance innovation. Living labs aim to span boundaries between different organizations, among others Triple helix actors, by acting as a network organization typically in a real-life environment to foster co-creation by user-groups. This paper presents critical factors of Living labs in boundary-spanning between Triple Helix actors. Derived from a mixed-method approach and applications in the healthcare sector, the three main critical factors turn out to be 1) an adequate user-group selection and involvement, specifically a rich interaction and absorption of its results, 2) a balanced involvement of all relevant actors, and 3) a sufficient (early) attention for values, both values of user-groups and values of the management. People-oriented Living labs tend to differ from institution-oriented Living labs regarding these critical factors. Further, universities tend to take on diverse roles and strength of involvement, while the business sector tends to be actively involved only if this has been set as an explicit aim at start. The paper closes with a summary and future research paths.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.77-82
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• 2015

Recently, multi-user massive MIMO (MU-Massive MIMO) network has attracted a lot of attention as a technology to accommodate explosively increasing mobile data traffic. However, the MU-Massive MIMO network causes a tremendous hardware complexity in a base station and computational complexity to select optimal set of users. In this paper, we thus propose a simple algorithm for selecting antennas and users while reducing the hardware and computational complexities simultaneously. The proposed scheme has a computational complexity of $O((N-S_a+1){\times}min(S_a,K))$, which is significantly reduced compared to the complexity of optimal scheme based on Brute-Force searching, $$O\left({_N}C_S_a\sum_{i=1}^{min(S_a,K)}_KC_i\right)$$, where N, $S_a$, and K denote the number of total transmit antennas, the number of selected antennas, and the number of all users, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.137-142
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• 1999

The purpose of this study is to develope a CAD-based tool for rasterization of polygonal vector map in AutoCAD. To identity the layer property of polygonal entity with user-defined coordinates as topology, algorithm in processing entity data of selection set that intersected with scan line was used, and the layers were extracted sequentially by sorted intersecting points in data-list. In addition to the functions for querying and modifying topology, two options for mapping were set up to construct plan projection type and to change meshes' properties in existing DTM data. In case of plan projection type, user-defined cell size of 3DFACE mesh is available for more detailed edge, and topological draping on landform can be executed in case of referring DTM data as an AutoCAD's drawing. The concept of algorithm was simple and clear, but some unexpectable errors were found in detecting intersected coordinates that were AutoCAD's error, not the utility's. Also, the routines to check these errors were included in algorithmic processing. Developed utility named MESHMAP was written in entity data control functions of AutoLISP language and dialog control language(DCL) for the purpose of user-oriented interactive usage. MESHMAP was proved to be more effective in data handling and time comparing with GRIDMAP module in LANDCADD which has similar function.