• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1105-1108
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• 2002

Real-time(RT) object-oriented(OO) distributed computing is a form of RT distributed computing realized with a distributed computer system structured in the form of an object network. Several approached proposed in recent years for extending the conventional object structuring scheme to suit RT applications, are briefly reviewed. Then the approach named the TMO(Time-triggered Message-triggered Object)structuring scheme was formulated with the goal of instigating a quantum productivity jump in the design of distributed time triggered simulation. The TMO scheme is intended to facilitate the pursuit of a new paradigm in designing distributed time triggered simulation which is to realize real-time computing with a common and general design style that does not alienate the main-stream computing industry and yet to allow system engineers to confidently produce certifiable distributed time tiggered simulation for safety-critical applications. The TMO structuring scheme is a syntactically simple but semantically powerful extension of the conventional object structuring approached and as such, its support tools can be based on various well-established OO programming languages such as C＋＋ and on ubiquitous commercial RT operating system kernels. The Scheme enables a great reduction of the designers efforts in guaranteeing timely service capabilities of application systems.

• Journal of The Korean Astronomical Society
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• v.53 no.1
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• pp.1-7
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• 2020

The recent study of Chae et al. (2017) found a one-to-one correspondence between plasma blobs outflowing along a ray formed after a coronal mass ejection (CME) and small X-ray flares. In the present work, we have examined the spatial configuration and the eruption process of the flares that are associated with the blobs by analyzing EUV images and magnetograms taken by the SDO/AIA and HMI. We found that the main flare and the successive small flares took place in a quadrupolar magnetic configuration characterized by predominant magnetic fields of positive polarity, two minor magnetic fragments of negative polarity, and a curved polarity inversion line between them, which suggests that the formation process of the blobs may be similar to that of the parent CME. We also found that the successive flares resulted in a gradual change of the quadrupolar magnetic configuration, and the relevant migration of flaring kernels. The three-dimensional geometry and the property of the current sheet, that is often supposed to be embedded in an observed post-CME ray, seem to keep changing because of mutual feedback between the successive flares and the temporal change of the magnetic field configuration. Our results suggest that the observed post-CME rays may not reflect the characteristics of the current sheet responsible for the impulsive phase of the flare.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.6
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• pp.325-334
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• 2016

Recently, Open Computing Language (OpenCL) has been proposed to provide a framework that supports heterogeneous computing platforms. By using an OpenCL framework, digital communication systems can support various protocols in a unified computing environment to achieve both high portability and high performance. This article introduces a parallel software decoder of Low Density Parity Check (LDPC) codes for China Multimedia Mobile Broadcasting (CMMB) on a heterogeneous platform. Each step of LDPC decoding has different parallelization characteristics. In this paper, steps suitable for task-level parallelization are executed on the CPU, and steps suitable for data-level parallelization are processed by the GPU. To improve the performance of the proposed OpenCL kernels for LDPC decoding operations, explicit thread scheduling, loop-unrolling, and effective data transfer techniques are applied. The proposed LDPC decoder achieves high performance by using heterogeneous multi-core processors on a unified computing framework.

• Nuclear Engineering and Technology
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• v.48 no.3
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• pp.650-659
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• 2016

As a type of accident-tolerant fuel, fully ceramic microencapsulated (FCM) fuel was proposed after the Fukushima accident in Japan. The FCM fuel consists of tristructural isotropic particles randomly dispersed in a silicon carbide (SiC) matrix. For a fuel element with such high heterogeneity, we have proposed a two-temperature homogenized model using the particle transport Monte Carlo method for the heat conduction problem. This model distinguishes between fuel-kernel and SiC matrix temperatures. Moreover, the obtained temperature profiles are more realistic than those of other models. In Part I of the paper, homogenized parameters for the FCM fuel in which tristructural isotropic particles are randomly dispersed in the fine lattice stochastic structure are obtained by (1) matching steady-state analytic solutions of the model with the results of particle transport Monte Carlo method for heat conduction problems, and (2) preserving total enthalpies in fuel kernels and SiC matrix. The homogenized parameters have two desirable properties: (1) they are insensitive to boundary conditions such as coolant bulk temperatures and thickness of cladding, and (2) they are independent of operating power density. By performing the Monte Carlo calculations with the temperature-dependent thermal properties of the constituent materials of the FCM fuel, temperature-dependent homogenized parameters are obtained.

• Journal of Forest and Environmental Science
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• v.31 no.4
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• pp.272-279
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• 2015

Xanthoceras sorbifolium is considered as bio-energy crops owing to the high oil content from kernel. This study was performed to analyze calorific value, crude ash content, ultimate ratio, crude lipid and fatty acid composition among seed sources. Calorific values ranged from $4,526.0\;cal\;g^{-1}$ to $7,377.2\;cal\;g^{-1}$ in seeds and kernels showed the highest value. Calorific values and crude ash contents were observed as significant difference among plantations and/or individuals (p>0.05). Kernel from SD-F plantation showed the highest calorific value and lower crude ash content. C content comprised 63.4%, the highest levels was detected from SD-F (64.8%). Crude lipid content in kernel observed as 54.5 g $100\;g^{-1}$ from SD-F. In contrast it was determined the lowest value from LN-JARS as 46.5 g $100\;g^{-1}$. The fatty acid composition of kernel was determined to those of oleic acid (31.3%) and linoleic acid (38.1%) from SD-F and LN-JARS. These results will be offered to useful information for breeding materials selection.

• KIISE Transactions on Computing Practices
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• v.23 no.1
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• pp.80-84
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• 2017

Existing operating systems experience scalability issues as the number of cores increases. The network I/O performance on manycore systems is faced with the major limiting factors of cache consistency costs and locking overheads. Legacy methods resolve this issue include the new microkernel-like operating system or modification of existing kernels; however, these solutions are not fully application transparent. In this study, we proposed a library that improves the network performance by separating system call context from user context and by applying the core affinity without any kernel and application modifications. Experiment results showed that our implementation can improve the network throughput of Apache by up to 30%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.863-872
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• 2002

Real-time(RT) object-oriented(00) distributed computing is a form of RT distributed computing realized with a distributed computer system structured in the form of an object network. Several approached proposed in recent years for extending the conventional object structuring scheme to suit RT applications, are briefly reviewed. Then the approach named the TMO(Time-triggered Message-triggered Object) structuring scheme was formulated with the goal of instigating a quantum productivity jump in the design of distributed time triggered simulation. The TMO scheme is intended to facilitate the pursuit of a new paradigm in designing distributed time triggered simulation which is to realize real-time computing with a common and general design style that does not alienate the main-stream computing industry and yet to allow system engineers to confidently produce certifiable distributed time triggered simulation for safety-critical applications. The TMO structuring scheme is a syntactically simple but semantically powerful extension of the conventional object structuring approached and as such, its support tools can be based on various well-established 00 programming languages such as C++ and on ubiquitous commercial RT operating system kernels. The Scheme enables a great reduction of the designers efforts in guaranteeing timely service capabilities of application systems.

• Korean Journal of Materials Research
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• v.30 no.10
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• pp.533-541
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• 2020

UO₂ kernels, a key component of fuel elements for high temperature gas cooled reactors, have usually been prepared by sol-gel methods. Sol-gel processes have a number of advantages, such as simple processes and facilities, and higher sphericity and density. In this study, to produce 900 ㎛-sized UO₂ particles using an external gelation process, contact length extension of the NH₃ gas of the broth droplets pass and the improvement of the gelation device capable of spraying 14 M-NH₄OH solution are used to form 3,000 ㎛-sized liquid droplets. To produce high-sphericity and high-density UO₂ particles, HMTA, which promotes the gelation reaction in the uranium broth solution, is added to diffuse ammonium ions from the outside of the gelation solution during the aging process and generate ammonium ions from the inside of the ADU gel particles. Sufficient gelation inside of ADU gel particles is achieved, and the density of the UO₂ spheres that undergo the subsequent treatment is 10.78 g/㎤; the sphericity is analyzed and found to be 0.948, indicating good experimental results.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.3
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• pp.161-171
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• 2010

As embedded systems adopt monolithic kernels, NAND flash memory is used for swap space of virtual memory systems. While flash memory has the advantages of low-power consumption, shock-resistance and non-volatility, it requires garbage collections due to its erase-before-write characteristic. The efficiency of garbage collection scheme largely affects the performance of flash memory. This paper proposes a novel garbage collection technique which exploits data redundancy between the main memory and flash memory in flash memory-based virtual memory systems. The proposed scheme takes the locality of data into consideration to minimize the garbage collection overhead. Experimental results demonstrate that the proposed garbage collection scheme improves performance by 37% on average compared to previous schemes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.159-162
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• 1999

This study was carried out to determine the optimum harvest date of unshelled immature peanuts and dried kernels from 60 to 120 days after flowering. Fresh pod yield of spanish-type variety, 'Shaedl-tangkong(SD)' reached a peak of 9,140kg/ ha at 70 (days after flowering(Aug. 13) while that of virginia-type variety, 'Daepoongtangkong(DP)' reached a peak of 8,820kg/ha at 90 days(Sept. 11) after flowering. SD and DP showed maximum fresh kernel yield of 6,090 and 6,470kg/ha at 90 days after flowering (Sept. 11), respectively, while dry kernel yield reached a peak of 3,300 and 3,720kg/ha at 110 days(Oct. 1), respectively. Oil content of SD and DP were the highest at 90 days and 100 days after flowering, respectively and the oil content of two varieties increased rapidly from 60 to 90 days. Tannin content of the seed hull of SD increased continuously until 110 days after flowering while that of DP maximized at 100 days. The tannin content of the two varieties increased rapidly from 60 to 100 days. Total sugar of SD and DP showed highest content at 60 days and 70 days after flowering, respectively and suger content decreased very rapidly until 80 days and after that sugar content kept nearly constant. Oil, tannin and total sugar content of spanish-type SD were higher than those of virginia-type DP.