• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.301-304
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• 2013

In this paper, to improve the fast boot and soft real-time for the responsiveness in Qplus with relative evaluation rather than an absolute evaluation using validated to perform the services actually used. Qplus is included soft real-time, fast booting, and file system technology. There is a development board that mounted on an embedded Linux and Qplus. AV (Audio / Video) group communications is ported on the development board for soft real-time multimedia streaming services and to evaluate the performance of communication. We performed three major evaluation such as booting time measurement experiment, own performance measurement experiments for soft real-time measurement experiment, and performance measurement experiments for via the network communication performance evaluation. They are a practical Qplus performance evaluation and analysis.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.587-597
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• 2005

Flash memory based embedded computing systems are becoming increasingly prevalent.These systems typically have to provide an instant start-up time. However, we observe that mounting a file system toy flash memory takes 1 to 25 seconds mainly depending on the flash capacity. Since the flash chip capacity is doubled in every year, this mounting time will soon become the most dominant reason of the delay of system start-up time Therefore, in this paper, we present instant mounting techniques for flash file systems by storing the In-memory file system metadata to flash memory when unmounting the file system and reloading the stored metadata quickly when mounting the file system. These metadata snapshot techniques are specifically developed for NOR- and NAND-type flash memories, while at the same time, overcoming their physical constraints. The proposed techniques check the validity of the stored snapshot and use the proposed fast trash recovery techniques when the snapshot is Invalid. Based on the experimental results, the proposed techniques can reduce the flash mounting time by about two orders of magnitude over the existing de facto standard flash file system, JFFS2.

• International Journal of Fluid Machinery and Systems
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• v.10 no.3
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• pp.240-253
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• 2017

Latin hypercube sampling is widely used design-of-experiment technique to select design points for simulation which are then used to construct a surrogate model. The exploration/exploitation properties of surrogate models depend on the size and distribution of design points in the chosen design space. The present study aimed at evaluating the performance characteristics of various surrogate models depending on the Latin hypercube sampling (LHS) procedure (sample size and spatial distribution) for a diverse set of optimization problems. The analysis was carried out for two types of problems: (1) thermal-fluid design problems (optimizations of convergent-divergent micromixer coupled with pulsatile flow and boot-shaped ribs), and (2) analytical test functions (six-hump camel back, Branin-Hoo, Hartman 3, and Hartman 6 functions). The three surrogate models, namely, response surface approximation, Kriging, and radial basis neural networks were tested. The important findings are illustrated using Box-plots. The surrogate models were analyzed in terms of global exploration (accuracy over the domain space) and local exploitation (ease of finding the global optimum point). Radial basis neural networks showed the best overall performance in global exploration characteristics as well as tendency to find the approximate optimal solution for the majority of tested problems. To build a surrogate model, it is recommended to use an initial sample size equal to 15 times the number of design variables. The study will provide useful guidelines on the effect of initial sample size and distribution on surrogate construction and subsequent optimization using LHS sampling plan.

• Journal of Preventive Medicine and Public Health
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• v.48 no.1
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• pp.10-17
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• 2015

Objectives: An outbreak of acute febrile illness occurred in the Republic of Korea Air Force boot camp from May to July 2011. An epidemiological investigation of the causative agent, which was of a highly infective nature, was conducted. Methods: Throat swabs were carried out and a multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) assay was performed to identify possible causative factors. Results: The mean age of patients who had febrile illness during the study period was 20.24 years. The multiplex RT-PCR assay identified respiratory syncytial virus (RSV) as the causative agent. The main symptoms were sore throat (76.0%), sputum (72.8%), cough (72.1%), tonsillar hypertrophy (67.9%), and rhinorrhea (55.9%). The mean temperature was $38.75^{\circ}C$ and the attack rate among the recruits was 15.7% (588 out of 3750 recruits), while the mean duration of fever was 2.3 days. The prognosis was generally favorable with supportive care but recurrent fever occurred in 10.1% of the patients within a month. Conclusions: This is the first epidemiological study of an RSV outbreak that developed in a healthy young adult group. In the event of an outbreak of an acute febrile illness of a highly infective nature in facilities used by a young adult group, RSV should be considered among the possible causative agents.

• Journal of Service Research and Studies
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• v.2 no.2
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• pp.81-90
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• 2012

Hardware technology will be widen the area of involvement. If the smart phone capabilities by the pc, PC-free areas will have much higher utilization of smartphones. even subway or bus. and You also enjoy the game and information that you want to connect to the Internet. Because of the advantages of these smartphones, the world market has become more spread by the phone. In the recently, You need to boot your PC or notebook. In this project, using the GPS feature, and Android hiker safety and convenience applications for the purpose. Consumer-friendly via search for the mobile devices around the mountain and near by mountain. and we may be able to help the trail more easily research and develope that were using.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.387-397
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• 2009

Physical activity has been increased with increased leasure time. Specifically, due to our mountainous geographical benefits, people actively participate in hiking and climbing as regular daily activities. Thus, more stable and comfortable hiking boots are required to walk on uneven and sloped rocky surface for a long period of time. 5 male subjects were recruited for testing planter pressure patterns of four different conditions(barefoot, classic hiking boot, stiffness 60 and stiffness 65). Tested hiking boots(stiffness 60 and stiffness 65) consists of the multiple pieces of outsoles as they are designed for a better shock absorption. In the results, some positive aspects of stiffness 60 and stiffness 65 such as wide contact area and powerful propulsive patterns at take off was observed compared to the classic hiking boots. Therefore, biomechanical development of hiking related clothes and footwear as well as equipment would be beneficial for people who enjoy hiking to maximize their quality of activities.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.1
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• pp.22-24
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• 2004

Snowboarding has become one of the premier alpine sports. The past decade has seen the popularity of snowboarding increase dramatically and the recent Winter Olympic Game showcased the strong visual appeal of the sport and the youth-oriented lifestyle and culture that accompanies it. The injury profile of the sport has also undergone change along with technological advances in boot and binding systems and the changing demographics of the sports participants. Central to the development of injury-prevention strategies is knowledge of the profile of injuries that occur, understanding those who are at particular risk and, if possible, the biomechanical factors involved in each injury type. Snowboarding was initially considered a dangerous, uncontrolled, alpine sport - an opinion based on little or no scientific evidence. That evidence has rapidly grown over the past decade and we now know that snowboard injury rates are no different to those in skiing; however, the injury profile is different. The purpose of this review is to give some perspective to the current snowboard injury literature. It discusses not only the demographic profile of those injured and the type of injuries that occur, but also gives some insight into the progress that has occurred in determining the impact of specific prevention strategies, such as splints to prevent injuries to the wrist/forearm. As the literature indicates, however, some things will not change, e.g. injuries are more likely to occur in beginners and lessons need to be reinforced as a fundamental aspect of any injury-prevention strategy.

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.3
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• pp.173-177
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• 1992

This experiment was carried out to determine the effect of harvesting dates on the dry matter yield and quality of "Kool grazer" winter rye(Seca1e cereale L.) as a soilage crop at the Forage Experimental Field of College of Agrlc. and Life Sciences, SNU, Suweon. Four-day harvasting interval was allocated to measure the growth, yield and quality of rye from April 14 to May 18, 1987. Rye was rapidly grown as 3 cm/day and the growth was linearly recorded from the elongation to flowering stage. The dry matter and in vitro digestible dry matter(1VDDM) yields per ha were linearly increased up to 0.26 and 0.19 tonlday from April 14 to May 4 and April 14 to 29, respectively, but major breaks in yield increases occurred at the 50% heading stage, than yields increased. The highest crude protein yield was observed at the first heading stage of April 29, then decreased. Acid detergent fiber (ADF) and crude protein(CP) contents of rye at the heading stage of May 5 were 35 and 17%, respectively and the nutritive value of rye in terms of ADF and CP contents was evaluated as the I st grade hay, but neutral detergent fiber(NDF) content of rye was 47 % at the boot stage ofApril 22 and evaluated as the 2nd grade hay in terms of NDF content. The results indicate that the first heading stage or the end of April would be the most suitable harvesting time for early maturing winter rye as a soilage crop in terms of yield and quality in the middle northwestern coast rcgion of Korea. of Korea.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.316-321
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• 2017

With the recent wide adoption of Linux in the fields of IoT, embedded, mobile, desktop and server industries, the importances of understanding the Linux system architecture as well as customizing the Linux system are increasing very steeply. Accordingly, the capabilities of building every component of Linux system from source code files have been important. The LFS (Linux From Scratch) site[1] guides the steps of building the basic Linux system from source files. The steps consist of build host preparation step, temporary system building step, final system building step, and system configuration and boot preparation step. However, the underlying concepts behind the steps used in building LFS are difficult to understand, particularly to the beginner. This paper analyzes the LFS build steps and reveal the core build concepts and principles used in each step. Additionally, this paper shows the measured package build times obtained from our build experience.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1696-1704
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• 2008

The conventional hard disk has been the dominant database storage system for over 25 years. Recently, hybrid systems which incorporate the advantages of flash memory into the conventional hard disks are considered to be the next dominant storage systems. Their features are satisfying the requirements like enhanced data I/O, energy consumption and reduced boot time, and they are sufficient to hybrid storage systems as major database storages. However, we need to improve traditional index management schemes based on B-Tree due to the relatively slow characteristics of hard disk operations, as compared to flashmemory. In order to achieve this goal, we propose a new index management scheme called FNC-Tree. FNC-Tree-based index management enhanced search and update performance by caching data objects in unused free area of flash leaf nodes to reduce slow hard disk I/Os in index access processes. Based on the results of the performance evaluation, we conclude that our scheme outperforms the traditional index management schemes.