• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.1
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• pp.55-63
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• 2001

There are many information objects and users in a large company. It is important issue how to control users access in order that only authorized user can access information objects, Traditional access control models do not properly reflect the characteristics of enterprise environment. This paper proposes an improved access control model for enterprise environment. The characteristics of access control in an enterprise are examined and a task role-based access control(T-RBAC) model founded on concept of classification of tasks is introduced. T-RBAC deals with each task differently according to its class, and supports task level access control and supervision role hierarchy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3780-3797
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• 2022

The estimation of radio map (RM) is a fundamental and critical task for the network planning and optimization performance of mobile communication. In this paper, a RM estimation method is proposed based on a deep dual learning structure. This method can simultaneously and accurately reconstruct the urban building map (UBM) and estimate the RM of the whole cell by only part of the measured reference signal receiving power (RSRP). Our proposed method implements UBM reconstruction task and RM estimation task by constructing a dual U-Net-based structure, which is named RadioCycle. RadioCycle jointly trains two symmetric generators of the dual structure. Further, to solve the problem of interference negative transfer in generators trained jointly for two different tasks, RadioCycle introduces a dynamic weighted averaging method to dynamically balance the learning rate of these two generators in the joint training. Eventually, the experiments demonstrate that on the UBM reconstruction task, RadioCycle achieves an F1 score of 0.950, and on the RM estimation task, RadioCycle achieves a root mean square error of 0.069. Therefore, RadioCycle can estimate both the RM and the UBM in a cell with measured RSRP for only 20% of the whole cell.

• The Mathematical Education
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• v.44 no.1 s.108
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• pp.15-40
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• 2005

This study basically investigates the meaning and properties of performance task applicable to mathematics classroom and it finds out how to run effectively performance task activities included in the present mathematics textbooks. To accomplish this, this study deals with twelves kinds of mathematics textbooks for ninth graders and is proceeded on the basis of textbook analysis and teacher interview. Considering a situation that in future mathematics textbook would be developed, according to the analytic results of this study, common understanding of performance task and qualified performance task are needed, a variety of tasks classified by differentiated level are needed. In addition, each task should be dealt with the contents related to curious and interesting real-life situations. Furthermore, fairness of checking and recording should be established and teachers' positive attitudes to applying performance tasks to math class are needed.

• Korean Management Science Review
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• v.26 no.1
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• pp.127-136
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• 2009

This paper purposes analyzing how task assignments influence on business process efficiency, and improving business process efficiency in Business Process Management (BPM) environments. For this purpose, task assignment is categorized into dynamic assignment and static assignment. Dynamic assignment binds a user to a task at process run-time, whereas static assignments assigns a task to a user at process build-time. So far, the influence of task assignment methods has not been studied. We, in this paper, analyze the business process efficiency using two different assigning rule, in terms of cycle time as a efficiency measure. The comparison result can provide a guideline for a company who wants to employ commercial BPM systems.

• The Journal of Korea Robotics Society
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• v.14 no.2
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• pp.104-113
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• 2019

Object manipulation in cluttered environments remains an open hard problem. In cluttered environments, grasping objects often fails for various reasons. This paper proposes a novel task and motion planning scheme to grasp objects obstructed by other objects in cluttered environments. Task and motion planning (TAMP) aims to generate a sequence of task-level actions where its feasibility is verified in the motion space. The proposed scheme contains an open-loop consisting of three distinct phases: 1) Generation of a task-level skeleton plan with pose references, 2) Instantiation of pose references by motion-level search, and 3) Re-planning task based on the updated state description. By conducting experiments with simulated robots, we show the high efficiency of our scheme.

• Journal of Information Processing Systems
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• v.17 no.3
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• pp.441-452
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• 2021

Federated learning provides an efficient integrated model for distributed data, allowing the local training of different data. Meanwhile, the goal of multi-task learning is to simultaneously establish models for multiple related tasks, and to obtain the underlying main structure. However, traditional federated multi-task learning models not only have strict requirements for the data distribution, but also demand large amounts of calculation and have slow convergence, which hindered their promotion in many fields. In our work, we apply the rank constraint on weight vectors of the multi-task learning model to adaptively adjust the task's similarity learning, according to the distribution of federal node data. The proposed model has a general framework for solving optimal solutions, which can be used to deal with various data types. Experiments show that our model has achieved the best results in different dataset. Notably, our model can still obtain stable results in datasets with large distribution differences. In addition, compared with traditional federated multi-task learning models, our algorithm is able to converge on a local optimal solution within limited training iterations.

• Educational Technology International
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• v.7 no.1
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• pp.21-37
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• 2006

This paper focuses on finding out visualization process by means of VTA(Visual Task Analysis) of expert teachers' simple task. Findings indicate teachers have coding schema of performing visual task as such; (a) the analyzing by reading and some activities in the task text, (b) conceptualizing or understanding in his/her own way, (c) the explaining of the action or product, (d) the searching by thinking or finding, (e) the decision of visualizing of the task. Expert teachers tried to visualize in the form of abstract graph, and to omit the object which was not directly related to the topic at the pilot study. VAT based on ground theory and protocol analysis was developed and performed. This case study suggests that an additional study for searching a guide and method might be beneficial for conducting a visual task analysis.

• Journal of Mechanical Science and Technology
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• v.16 no.8
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• pp.1053-1063
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• 2002

This paper presents a robust nonlinear controller for a f degree of freedom (DOF) parallel manipulator in the task space coordinates. The proposed control strategy requires information on orientations and translations in the task space unlike the joint space or link space control scheme. Although a 6 DOF sensor may provide such information in a straightforward manner, its cost calls for a more economical alternative. A novel indirect method based on the readily available length information engages as a potential candidate to replace a 6 DOF sensor. The indirect approach generates the necessary information by solving the forward kinematics and subsequently applying alpha-beta-gamma tracker With the 6 DOF signals available, a robust nonlinear task space control (RNTC) scheme is proposed based on the Lyapunov redesign method, whose stability is rigorously proved. The performance of the proposed RNTC with the new estimation scheme is evaluated via experiments. First, the results of the estimator are compared with the rate-gyro signals, which indicates excellent agreement. Then, the RNTC with on-line estimated 6 DOF data is shown to achieve excellent control performance to sinusoidal inputs, which is superior to those of a commonly used proportional-plus-integral-plus-derivative controller with a feedforward friction compensation under joint space coordinates and the nonlinear controller under task space coordinates.

• Korean Institute of Interior Design Journal
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• v.21 no.1
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• pp.119-126
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• 2012

The purpose of this study is to suggest a strategy of creating sustainable city's streets by extracting a elements related the task related with society, economic, and environment. The method of this study is as follows. First step, we extract main task for developing sustainable settlements through studying literature review. Second step, based on the task for sustainable settlements, we generate various elements for developing sustainable street environments. Third step, we carry out a survey targeting experts related to field of urban environment. Fourth step, we analyze their priority about developing elements and the difference between groups. Last step, through correlation analysis between three task and elements for developing sustainable streets, we discuss the specific application around developing elements. The result of this study is as follows. Firstly, from a social point of view, the task related to connecting of historical and cultural characteristic is the most important thing. In a environmental view, it illustrates that application of technologies based on IT is more important than use of sustainable land. In a economic paint of view, it presents that the elements of city security & disasters are important.

• The Mathematical Education
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• v.55 no.1
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• pp.107-127
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• 2016

The purpose of this study was to explore the possibility of mathematical instruction through performance task activities based on the The Backward Design, which was suggested at first by Wiggins & McTighe in 1998. The Design deals with a performance assessment task involving the whole objective and its entire content of a lesson. Based on the Backward Design, this study established the mathematical instructional materials, which deal with the concept of 'the sector' taught in middle school, with one large performance task including three small tasks. It is important that in the lesson students be guided to achieve the several learning goals by themselves through reasoning activities. For this purpose, a formal interview was carried out by the subject of three middle school mathematics teachers. As a result, in order to implement the instruction utilizing the performance tasks more efficiently in future, it is required that a large performance task should be selected or developed including the content or problem contexts to be relevant with the real-life challenging situations. In addition, to make students enhance reasoning skills, it is strongly requested that the tasks including the utilization of supplementary materials such as technological devices or manipulatives be dealt with in a lesson.