• 전기의세계
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• v.18 no.3
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• pp.15-23
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• 1969

A combinational circuit is one of the fundamental elements in digital circuits, containing electronic computers. W.A. Davis presented a new approach to the problem of assigning binary input codes so that the combinational circuits necessary to realize the given output functions may be minimized. This paper has derived an algorithm for determining the actual cost of a given assignment scheme in Davis method. First, the combinations of partitions realizing the output functions are obtained and then those among them implementing all of the output functions are found by using a table. In consequence it has been proved that by this algorithm the process of the assignment in a schcme with 16 states and 3 determined partitions can be reduced to 1/10$^{6}$ .

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.3
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• pp.19-26
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• 2002

Despite the unfamiliar term "multifunctionality of agriculture" and the tremendous number of debates made over the past 10 years, multiple benefits from paddy rice farming in the Asian monsoon region are very significance due to the various inherent characteristics of paddy rice in this lesion. They were identified as rural vitalization, social security, nature and environmental preservations, and social and cultural functions. As studies estimating the monetary value of nature and environmental functions in Korea and Japan revealed, the economic value of multifunctionality from paddy rice farming reached to 70∼150% of total annual rice production cost of each country, and would have been even higher, had other functions been included. Therefore, interdisciplinary and international researches within the monsoon Asian countries are necessary to develop counter-measure logics against the Western dry land farming countries, emphasizing the efforts to disseminate worldwide the significance and recognition of the multifunctionality of paddy rice farming under the Asian monsoon climate.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.512-519
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• 2002

In this paper, we implemented a loom component to be placed in a window and a looms management system which is able to connect database and to process various queries. The implemented system has aggregate query p개cessing functions for the loom components existing in the selected area by the mouse and it also has high level query processing functions represented with chart and pivot table; it can be used as a decision support system. The proposed system can detect temporal or persistent problems of the looms. Therefore it can be used to raise the productivity and to reduce the cost in textile companies by coping with the situation properly.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.293-298
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• 1997

The H$_{\infty}$robust controller fur the reactor power control system is designed by use of the mixed weight sensitivity. The system is configured into the typical two-port model with which the weight functions are augmented. Since the solution depends on the weighting functions and the problem is of non-convex, the genetic algorithm is used to determine the weighting functions. The cost function applied in the genetic algorithm permits the direct control of the power tracking performances. In addition, the actual operating constraints such as rod velocity and acceleration can be treated as design parameters. Compared with the conventional approach, the controller designed by the genetic algorithm results in the better performances with the realistic constraints. Also, it is found that the genetic algorithm could be used as an effective tool in the robust design. robust design.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.627-635
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• 2019

In this study, we developed for processing complex features using CAM software that satisfies precision for example practice and related qualification tests suiTable for CNC training purposes. In addition, functions such as location control, speed control, and processing path generation, which are the main functions of CNC machining machines, were constructed using small equipment parts, servo motors, inverters, general purpose PCs, and commercial NC software and researched with the goal of developing low-cost education equipment. In the static accuracy inspection, the degree of machine when measuring the parallelism of the X, Y and Z axes and the vibration of the main shaft did not reach the allowable value. However, we have obtained a finished product that satisfies the CNC machine book sample shape machining, detailed functions of the position control function of the CNC machine tool, linear interpolation function, circular interpolation function, and tool offset function. In the qualification test shape processing, a shape with a degree of 1/100 mm was processed to obtain position accuracy that satisfied the tolerance.

• Journal of information and communication convergence engineering
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• v.17 no.3
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• pp.185-190
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• 2019

The explosive growth of data traffic and services has created cost challenges for networks. Studies have attempted to effectively apply network slicing in fifth generation networks to provide high speed, low latency, and various compatible services. However, in network slicing using mixed-integer linear programming, the operation count increases exponentially with the number of physical servers and virtual network functions (VNFs) to be allocated. Therefore, we propose an efficient slice allocation method based on cluster technology, comprising the following three steps: i) clustering physical servers; ii) selecting an appropriate cluster to allocate a VNF; iii) selecting an appropriate physical server for VNF allocation. Solver runtimes of the existing and proposed methods are compared, under similar settings, with respect to intra-slice isolation. The results show that solver runtime decreases, by approximately 30% on average, with an increase in the number of physical servers within the cluster in the presence of intra-slice isolation.

• Journal of Sensor Science and Technology
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• v.31 no.3
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• pp.139-144
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• 2022

Advanced tactile sensors are receiving significant attention in various industries such as extended reality, electronic skin, organic user interfaces, and robotics. The capabilities of advanced tactile sensors require a variety of functions, including position sensing, pressure sensing, and material recognition. Moreover, they should comsume less power and be bio-friendly with human contact. Recently, a tactile sensor based on the triboelectrification effect was developed. Triboelectric tactile sensors have the advantages of wide material availability, simple structure, and low manufacturing cost. Because they generate electricity by contact, they have low power consumption compared to conventional tactile sensors such as capacitive and piezoresistive. Furthermore, they have the ability to recognize the contact material as well as execute position and pressure sensing functions using the triboelectrification effect. The aim of this study is to introduce the progress of research on triboelectrification-based tactile sensors with various functions such as position sensing, pressure sensing and contact material recognition.

• Journal of Korea Trade
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• v.25 no.2
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• pp.196-219
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• 2021

Purpose - We attempted to empirically verify the effects of managerial attributes on cost stickiness in exporters. Exporters are often affected not only by external factors such as exchange rate but also by internal factors such as managerial attributes regarding their business activities. Because cost stickiness is the product of a manager's decision-making, it has been considered that managerial attributes have a great influence on the behavior. Therefore, our study was intended to find out whether cost stickiness shows differentiated aspects depending on managerial attributes in exporters. Design/methodology - We considered two managerial attributes: CEO power and managerial overconfidence. First, CEO power was measured as CEO pay slice. In addition, managerial overconfidence was measured based on three methodologies presented by previous studies. To measure cost stickiness, we used multiple methodologies presented by prior research. Findings - The results of our empirical analysis are as follows. First, in export firms, the greater CEO power is, the greater cost stickiness is. This result suggested that export managers with great influence little respond to temporary sales decrease promptly, little reduce related production costs flexibly in preparation for future sales recovery, but leave room to endure costs for idle resources. Second, the greater managerial overconfidence is, the greater cost stickiness is. This result indicated that export managers with great overconfidence on their decision-making often view the prospect for sales recovery positively; therefore, they little respond to temporary sales decrease immediately, little reduce related production costs flexibly for future sales recovery, but leave room to endure costs for idle resources. Third, export managers with great influence in their businesses and great overconfidence in their decision-making tend to show relatively great cost stickiness. The results proposed that the combination of the two factors functions to make cost stickiness greater. Originality/value - Our study is differentiated from extant studies in that we provided empirical evidence of the effects of managerial attributes on their business activities in exporters. Specifically, we verified the effects of managerial attributes on cost stickiness in Korean exporters. The results of our study are expected to contribute to providing useful information for exporters and start-ups.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.498-503
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• 1991

This paper presents a framework of a optimal supervisory controller, which consists of decision rules and the supervisory controller proposed by Ramadge and Wonham. From the presented framwork we obtain optimal control patterns minimizing the given cost functions. The properties of the presented optimal supervisory controller are discussed. Two examples are given to illustrate a designing method of the optimal supervisory controller.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.4
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• pp.145-152
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• 2019

All machines deteriorate in performance over time. The phenomenon that causes such performance degradation is called deterioration. Due to the deterioration, the process mean of the machine shifts, process variance increases due to the expansion of separate interval, and the failure rate of the machine increases. The maintenance model is a matter of determining the timing of preventive maintenance that minimizes the total cost per wear between the relation to the increasing production cost and the decreasing maintenance cost. The essential requirement of this model is that the preventive maintenance cost is less than the failure maintenance cost. In the process mean shift model, determining the resetting timing due to increasing production costs is the same as the maintenance model. In determining the timing of machine adjustments, there are two differences between the models. First, the process mean shift model excludes failure from the model. This model is limited to the period during the operation of the machine. Second, in the maintenance model, the production cost is set as a general function of the operating time. But in the process mean shift model, the production cost is set as a probability functions associated with the product. In the production system, the maintenance cost of the equipment and the production cost due to the non-confirming items and the quality loss cost are always occurring simultaneously. So it is reasonable that the failure and process mean shift should be dealt with at the same time in determining the maintenance time. This study proposes a model that integrates both of them. In order to reflect the actual production system more accurately, this integrated model includes the items of process variance function and the loss function according to wear level.