• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.45
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• pp.357-364
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• 1998

This study deals with the performance evaluation of writing for designing handwriting instruments ergonomically. Experimental tests were executed on ballpoint pen., felt-tip pen, pencil, sharp-pencil, and fountain pen for ease of use and reduction of the muscles fatigue. The writing time and the degree of comfort of writing by subjects were measured on the diameters of five writing instruments. The results indicated that the ballpoint pen was rated significantly superior to the others in writing speed attribute and the instrument with the least fatigue was the fountain pen. There was a significant interaction effect between the types of instruments and their size in diameters. The diameter of instruments for considering time and comfort together was verified that the size of 9.5mm was efficient for ballpoint pen, the size of 8.1mm for felt-tip pen, the size of 7.5mm for pencil, the size of 8.2mm for sharp-pencil, and the size of 9.1mm for fountain pen.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.2
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• pp.55-63
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• 2014

In this paper, we introduce the performance evaluation of data archive system for saving correlation result of Daejeon correlator with high-data rate. Daejeon correlator supports various correlation modes, but the speed of correlation result is affected by correlator according to the integration time in each mode. Maximum data rate of Daejeon correlator is 1.4GB/s in case of C1 mode with 25.6ms integration time. In this research, the performance evaluation of the proposed data archive system is conducted for saving correlation results connected with 4 10GbE optical cable with VCS (VLBI Correlation Subsystem), which is the core system of Daejeon correlator. For the experiments, the data archive system for 2 benders was selected and benchmark test was performed. In this paper, the developed data generation program of VCS correlation result file for benchmark test and evaluation results are described.

• The Journal of Korean Academy of Sensory Integration
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• v.15 no.1
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• pp.10-20
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• 2017

Objective : The purpose of this study was to investigate the effect of proprioceptive-vestibular based sensory integrative intervention on handwriting and fine motor function in elementary school students in grades 1 to 3. Methods : In this study, eight students in an elementary school in Busan were enrolled. The intervention was conducted twice a week from May to October, 2016, and a total of 14 intervention sessions were conducted. In order to evaluate the writing ability and the fine-motor exercise ability before and after the intervention, the fine-motor movement items of the Korean alphabet writing test and the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) evaluation were used. Results : There was a statistically significant difference between the total scores of consonant writing and the Korean alphabet writing assessment after the intervention. In BOTMP-Fine motor, the response speed items showed statistically significant difference. Visual-motor control scores increased during intervention, but the statistical significance was not found. Conclusion : Sensory integration interventions might have positive effects on elementary school students' writing skills and fine motor functions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.1 s.232
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• pp.81-87
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• 2005

A fracture of hand held device, such as radio, TV and CD-RW drive, mainly occurs due to drop situation. For CD-RW drive, the need of high reading/writing speed in conjunction with low price accelerates the fracture of the device. Computer simulation can reduce the period of development and enhance impact characteristic of device. In this study, the detailed finite element model of CD-RW drive was developed to predict the damage under drop conditions. Material property for shock absorbing damper was obtained from tensile test of raw material. A MOONEY-RIVLIN type rubber in LS-DYNA was used as the material model of damper. To assess the reliability of the developed model, drop test at 200G-2msec and 150G-10msec condition was conducted and acceleration at pick-up was compared.

• Journal of Internet Computing and Services
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• v.13 no.5
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• pp.55-64
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• 2012

Nowadays, as Cloud computing becomes popular, a need for a DFS(distributed file system) is increased. But, in the current Cloud computing environments, there is no DFS framework that is sufficient to protect sensitive private information from attackers. Therefore, we designed and proposed a secure scheme for distributed file systems. The scheme provides confidentiality and availability for a distributed file system using a secret sharing method. In this paper, we measured the speed of encryption and decryption for our proposed method, and compared them with that of SEED algorithm which is the most popular algorithm in this field. This comparison showed the computational efficiency of our method. Moreover, the proposed secure read/write model is independent of Hadoop DFS structure so that our modified algorithm can be easily adapted for use in the HDFS. Finally, the proposed model is evaluated theoretically using performance measurement method for distributed secret sharing model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2784-2790
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• 2015

The column-oriented database storage is a very advanced model for large-volume data transactions because of its superior I/O performance. Traditional data storages exploit row-oriented storage where the attributes of a record are placed contiguously in hard disk for fast write operations. However, for search-mostly data warehouse systems, column-oriented storage has become a more proper model because of its superior read performance. Recently, solid state drive using flash memory is largely recognized as the preferred storage media for high-speed data analysis systems. In this research, we propose a new transaction recovery scheme for a column-oriented database environment which is based on a flash media file system. We improved traditional shadow paging schemes by reusing old data pages which are supposed to be invalidated in the course of writing a new data page in the flash file system environment. In order to reuse these data pages, we exploit reused shadow list structure in our column-oriented shadow recovery(CoSR) scheme. CoSR scheme minimizes the additional storage overhead for keeping shadow pages and minimizes the I/O performance degradation caused by column data compression of traditional recovery schemes. Based on the results of the performance evaluation, we conclude that CoSR outperforms the traditional schemes by 17%.

• Korean Journal of Heritage: History & Science
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• v.57 no.1
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• pp.82-108
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• 2024

With the transition of archaeological recording method's transition from analog to digital, the 3D scanning technology has been actively adopted within the field. Research on the digital archaeological digital data gathered from 3D scanning and photogrammetry is continuously being conducted. However, due to cost and manpower issues, most buried cultural heritage organizations are hesitating to adopt such digital technology. This paper aims to present a digital recording method of relics utilizing open-source software and photogrammetry technology, which is believed to be the most efficient method among 3D scanning methods. The digital recording process of relics consists of three stages: acquiring a 3D model, creating a joining map with the edited 3D model, and creating an digital drawing. In order to enhance the accessibility, this method only utilizes open-source software throughout the entire process. The results of this study confirms that in terms of quantitative evaluation, the deviation of numerical measurement between the actual artifact and the 3D model was minimal. In addition, the results of quantitative quality analysis from the open-source software and the commercial software showed high similarity. However, the data processing time was overwhelmingly fast for commercial software, which is believed to be a result of high computational speed from the improved algorithm. In qualitative evaluation, some differences in mesh and texture quality occurred. In the 3D model generated by opensource software, following problems occurred: noise on the mesh surface, harsh surface of the mesh, and difficulty in confirming the production marks of relics and the expression of patterns. However, some of the open source software did generate the quality comparable to that of commercial software in quantitative and qualitative evaluations. Open-source software for editing 3D models was able to not only post-process, match, and merge the 3D model, but also scale adjustment, join surface production, and render image necessary for the actual measurement of relics. The final completed drawing was tracked by the CAD program, which is also an open-source software. In archaeological research, photogrammetry is very applicable to various processes, including excavation, writing reports, and research on numerical data from 3D models. With the breakthrough development of computer vision, the types of open-source software have been diversified and the performance has significantly improved. With the high accessibility to such digital technology, the acquisition of 3D model data in archaeology will be used as basic data for preservation and active research of cultural heritage.