• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1066-1069
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• 2004

Recently the monitoring system of tool setup in high speed precision machining tool is required for manufacturing products that have highly complex and small shape, high precision and high function. It is very important to reduce time to setup tool in order to improve the machining precision and productivity and to protect the breakage of cutting tool as the shape of product is smaller and more complex. Generally, the combination of errors that geometrical clamping error of fixing tool at the spindle of machining center and the asynchronized error of driving mechanism causes that the run-out of tool reaches to 3∼20 times of the thickness of cutting chip. And also the run-out is occurred by the misalignment between axis of tool shank and axis of spindle and spindle bearing in high speed rotation. Generally, high speed machining is considered when the rotating speed is more than 8,000 rpm. At that time, the life time of tool is reduced to about 50％ and the roughness of machining surface is worse as the run-out is increased to 10 micron. The life time of tool could be increased by making monitoring of tool-setting easy, quick and precise in high speed machining center. This means the consumption of tool is much more reduced. And also it reduces the manufacturing cost and increases the productivity by reducing the tool-setup time of operator. In this study, in order to establish the concept of tool-setting monitoring the measuring method of the geometrical error of tool system is studied when the spindle is stopped. And also the measuring method of run-out, dynamic error of tool system, is studied when the spindle is rotated in 8,000 ∼ 60,000 rpm. The dynamic phenomena of tool-setup is analyzed by implementing the monitoring system of rotating tool system and the noncontact measuring system of micro displacement in high speed.

• Journal of Korea Multimedia Society
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• v.2 no.2
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• pp.155-165
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• 1999

Because the encrypted data is random, there is a possibility of threat that attacker reveals the secret data. On the other hand, as the image steganogrphy is to embed the secret data into cover image and to transmit the embedded image to receiver, an attacker could not know the existence of secret data even though he/she sees the embedded image, therefore the sender may reduce the threat of attack. In the image steganography, the secret data is embedded by modifying value of pixels as a form of noise. If the secret data is embedded into gray image, the degradation of image quality results from the modifications of image due to noise. Therefore many methods have been proposed to embed the secret data while dethering the gray image, but the existing method using error-diffusion has a problem that any patterns such as a diagonal lines or vertical take place due to embedding the secret data at the fixed interval. To solve this problem and to improve the existing method, we proposed the new method that embeds the secret data at changed point with respect to 1's run-length or at the position where has the minimum difference with the original dithered value. We evaluated the performance of the proposed method by computer simulation.

• KIISE Transactions on Computing Practices
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• v.23 no.7
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• pp.452-457
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• 2017

Linux is a general-purpose operating system that supports several schedulers, allowing different schedulers to coexist. In addition, Linux uses the Control Group (cgroup) to reserve CPU resources for task groups that follow the real-time (SCHED_FIFO, SCHED_RR) and non-real-time (SCHED_NORMAL) scheduler policies, except for the deadline scheduler (SCHED_DEADLINE). The cgroup performs the schedulability analysis to guarantee the reserved CPU resource as much as possible. However, current implementation of the schedulability analysis does not distinguish between deadline tasks and real-time tasks. Therefore, if these deadline tasks and real-time task groups coexist, there is a case where the resource reservation for the real-time task group is rejected. In this paper, we analyze the problems in the schedulability analysis for real-time task groups of Linux cgroups and propose patches to solve these problems.

• The KIPS Transactions:PartB
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• v.10B no.4
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• pp.429-442
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• 2003

In this paper, we describe an address image recognition system for automatic processing of standard- size letter mail. The inputs to the system are gray-level mail piece images and the outputs are delivery point codes with which a delivery sequence of carrier can be generated. The system includes five main modules; destination address block location, text line separation, character segmentation, character recognition and finally address interpretation. The destination address block is extracted on the basis of experimental knowledge and the line separation and character segmentation is done through the analysis of connected components and vortical runs. For recognizing characters, we developed MLP-based recognizers and dynamical programming technique for interpretation. Since each module has been implemented in an independent way, the system has a benefit that the optimization of each module is relatively easy. We have done the experiment with live mail piece images directly sampled from mail sorting machine in Yuseong post office. The experimental results prove the feasibility of our system.

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.102-110
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• 2014

It is a time to change the investment system for performances of co-producing according to development of the environment of performing arts in Korea. If we keep producing performances through the conventional method of the investment, we soon fall behind because production costs will increase by extension of the performance period. Investment companies generally require to the production company the investment principal guarantee as a condition for a investment. Producing companies have been producing performance with only ticket revenue and money of investment companies without their own money. Those two unreasonable things have raised a risk. So first of all, it is necessary to account marginal cost instead of average cost to decide more exactly open-running of performance. Second, it is necessary to change total cost as an investment parameter to production cost to avoid the unreasonable demands, such as a principal guarantee to production company. Therefore, we have to accept the budget planning of the United States to account the marginal cost and the production cost.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.12
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• pp.891-898
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• 2009

This paper suggests producer/consumer-based Data Binder enabling applications and biomedical devices developed by mutually different vendors to transfer data dynamically. Data Binder is implemented as a bundle of OSGi platform providing component-based programming model and service-oriented operation architecture. Data Binder complements the disadvantage of OSGi WireAdmin service enabling static data delivery between a producer and a consumer of data. Data Binder normalizes an application requirement as an application descriptor and a device capability as a device descriptor so that it enables dynamic data delivery by making data producer/consumer pair in runtime. Therefore, Data Binder can be used as a connection management of a data link between a data producer and a data consumer in sensor-based application development. The object of this paper is to provide the facility of the healthcare service development by separating a data producer such as a biomedical device from a data consumer such as a healthcare application.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.205-206
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• 2018

Recently, interest in unmanned vehicles, autonomous vehicles and connected cars has increased, and autonomous driving capability is also increasing. Depending on the autonomous driving ability, the maximum number of steps is divided into 6 steps. The higher the step, the less the involvement of the person in the running, and the person does not need to be involved at the highest stage. Today's autonomous vehicles have been developed in stages 4 to 5, but solutions are not clearly defined in case of an accident, so only the test run is possible. Such an accident occurring during traveling is almost inevitable, and it is judged who has made a mistake in case of an accident, which increases the punishment for the accident. Although a black box is used to clarify such a part, it is easy to delete a photographed image, and it is difficult to solve an accident such as a hit-and-run. In this paper, we design a driving record system using black chain to solve such an accident.

• The KIPS Transactions:PartA
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• v.13A no.7 s.104
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• pp.561-572
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• 2006

Performance of the mobile devices greatly depends on the efficient resource management because they are usually resource-restricted. In particular, the dynamic storage allocation algorithms very important part of the mobile device's operating system and OS-like software platform. The existing dynamic storage allocation algorithms did not consider application's execution style and the type, life-time, and characteristics of memory objects that the application uses. Those algorithms, as a result, could not manage memory efficiently Therefore, this Paper analyzes the mobile application's execution characteristics and proposes anew dynamic storage allocation algorithm which saves the memory space and improves mobile application's execution speed. The test result shows that the proposed algorithm works 6.5 times faster than the linked-list algorithm[11], 2.5 times faster better than the Doug. Lea's algorithm[12] and 10.5 times faster than the Brent algorithm[14].

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.487-501
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• 2017

A machine vision system (MVS) is a computer system that utilizes one or more image-capturing devices to provide image data for analysis and interpretation. Recently there have been a number of industrial- and medical-device applications where control charts have been proposed for use with image data. The use of image-based control charting is somewhat different from traditional control charting applications, and these differences can be attributed to several factors, such as the type of data monitored and how the control charts are applied. In this paper, we investigate the adjustment effect of image size and region of interest (ROI) size, when we use control charts to monitor grayscale image data in industry.

• Journal of Navigation and Port Research
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• v.29 no.8 s.104
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• pp.741-746
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• 2005

This paper proposes a method for designing layout on the yard and evaluating alternative designs of the layout by applying simulation The design method is based on the concepts of the conventional port container terminal with yard layout. In general, yard design of the container terminal consists of the two major parts. One is to divide yard area between the number of sections and runs and the other is to decide the number of equipment including yard truck and yard crane. In the past days, this design was depended on the experience of the terminal operator and the reproduction of the conventional terminal layout because it is a very complex problem to be considering facilities and equipments. In this paper, we suggest a design method as a conceptual procedure used simulation method The number of sections and runs on yard area, the number of yard truck per container crane, and the number of yard crane per run are decided using simulation In addition, the traffic flow among blocks on yard layout is estimated in terms of rate.