• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.58.4-59
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• 2020

We present preliminary results of 1.1 and 1.3 mm dust continuum and 12CO (J=2-1) line data obtained with the Submillimeter Array toward six cores harboring Class 0/I objects in the λ Orionis cloud. They are located in bright rimmed clouds, which are exposed to the far-ultraviolet radiation field by the O-type star λ Ori. Compact dust continuum emission is observed from all six cores. Among the six cores, only one core G196.92-10.37 shows a signature of binarity with separation of 4000 AU. The numbers of singles and binaries in our sample are five and one, respectively and the derived multiplicity frequency (MF) is 0.17. This value is lower than those found in the binary surveys toward Class 0/I objects, which may be a hint for negative feedback by the nearby massive star, lambda Ori. The derived excitation temperature (Tex) using 12CO emission shows a lower median value (20 K) than those of triggered star-forming regions (30 K). The lower MF and Tex support our previous study that star formation was not triggered in the λ Orionis cloud. We aim to further investigate whether the Class 0/I YSOs in the λ Orionis cloud have less circumstellar materials and smaller accretion rates than in other filamentary clouds (e.g., Orion A & B), which might be attributed to negative feedback from the massive star in limiting accretion of protostars.

• Journal of the Korea Society of Computer and Information
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• v.17 no.8
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• pp.11-19
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• 2012

In this paper, we propose a power-efficient scheduling scheme for lightly loaded multicore processors which contain more processing cores than running tasks. The proposed scheme activates a portion of available cores and inactivates the other unused cores in order to save power consumption. The tasks are assigned to the activated cores based on a heuristic mechanism for fast task assignment. Each activated core executes its assigned tasks with the optimal clock frequency which minimizes the power consumption of the tasks while meeting their deadlines. Evaluation shows that the proposed scheme saves up to 78% power consumption of the previous method which activates as many processing cores as possible for the execution of the given tasks.

• The Journal of Advanced Prosthodontics
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• v.7 no.3
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• pp.199-206
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• 2015

PURPOSE. The present study investigated the influences of various gypsum materials on the precision of fit of CAD/CAM-fabricated prostheses and analyzed their correlation with surface roughness. MATERIALS AND METHODS. The master model of the mandibular right first molar was replicated, and four experimental groups based on two types of Type IV stone (GC Fujirock EP, Die keen) and two types of scannable stone (Aesthetic-Basegold, Everest Rock) were created to include a total of 40 specimens, 10 in each group. The surface roughness of the working models for the respective experimental groups was measured. Once the zirconia cores had been fabricated, the marginal and internal fits were measured with a digital microscope using the silicone replica technique. The mean and standard deviation of the respective points of measurement were computed and analyzed through the one-way ANOVA and Tukey's HSD test. The correlation between surface roughness and the precision of fit of the zirconia core was analyzed using the Pearson correlation analysis (${\alpha}$=.05). RESULTS. The zirconia cores fabricated from the scannable stone working models exhibited a superior precision of fit as compared to those fabricated from the Type IV stone working models. The correlation analysis results showed a clear positive correlation between surface roughness and the precision of fit of zirconia cores in all of the experimental groups (P<.05). CONCLUSION. The results confirmed that the surface roughness of dental working models has a decisive influence on the precision of fit of zirconia cores.

• Journal of Environmental Science International
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• v.27 no.8
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• pp.723-735
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• 2018

In this study, to investigate an optimal configuration method for the modeling system, we performed an optimization experiment by controlling the types of compilers and libraries, and the number of CPU cores because it was important to provide reliable model data very quickly for the national air quality forecast. We were made up the optimization experiment of twelve according to compilers (PGI and Intel), MPIs (mvapich-2.0, mvapich-2.2, and mpich-3.2) and NetCDF (NetCDF-3.6.3 and NetCDF-4.1.3) and performed wall clock time measurement for the WRF and CMAQ models based on the built computing resources. In the result of the experiment according to the compiler and library type, the performance of the WRF (30 min 30 s) and CMAQ (47 min 22 s) was best when the combination of Intel complier, mavapich-2.0, and NetCDF-3.6.3 was applied. Additionally, in a result of optimization by the number of CPU cores, the WRF model was best performed with 140 cores (five calculation servers), and the CMAQ model with 120 cores (five calculation servers). While the WRF model demonstrated obvious differences depending on the number of CPU cores rather than the types of compilers and libraries, CMAQ model demonstrated the biggest differences on the combination of compilers and libraries.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.10 s.352
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• pp.140-150
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• 2006

In this paper, we present a new hardware architecture for testing various cores embedded in SoC. The conventional solutions need much testing time since only one core is tested at single test period. To enhance this, S-TAM, a novel test architecture, and its controller which enable parallel testing of various cores are proposed. S-TAM supports bus sharing to broadcast testing and cores to be tested are selected by using it. In addition, S-TAM controller enables the effective SoC test by simultaneous controlling the various test cores which are based on the different test architectures like IEEE 1149.1 and IEEE 1500.

• Publications of The Korean Astronomical Society
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• v.29 no.2
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• pp.29-34
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• 2014

We have observed the deuterated methanol, $CH_3OD$, toward the hot core MM1 in the massive star-forming region DR21 (OH) using the Submillimeter Array with a high angular resolution of about 1 arcsecond. The position of the hot core associated with the sub-core MM1a was confirmed to coincide with the continuum peak where an embedded young stellar object is located. The column density of $CH_3OD$ was found to be about $(2{\pm}1){\times}10^{16}cm^{-2}$ toward the MM1a center. The abundance ratio $CH_3OD/CH_3OH$ was measured to be ~ 0.45, which is about the median value for low mass star-forming cores but much larger than those of the massive star-forming cores. The ratio is believed to change depending on, for example, the chemical condition, the temperature and the density of the source. This ratio may further depend on the evolutionary phase especially in the massive-star-forming cores. The sub-core MM1a is thought to be in the very early phase of star formation. This large abundance ratio found in this source indicates that even the massive star-forming cores, during a relatively short period in the very early stage of star formation, may also show a chemical state resulted from the cold and dense pre-collapsing phase, the enhanced deuteration as found in low mass star-forming cores.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.205-212
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• 2010

This paper describes a core generator (FCore_Gen) which generates Verilog-HDL models of 640 different FFT/IFFT cores with selected parameter value for OFDM-based communication systems. The generated FFT/IFFT cores are based on in-place single memory architecture and use a hybrid structure of radix-4 and radix-2 DIF algorithm to accommodate various FFT lengths. To achieve both memory reduction and the improved SQNR, a conditional scaling technique is adopted, which conditionally scales the intermediate results of each computational stage. The cores synthesized with a $0.35-{\mu}m$ CMOS standard cell library can operate with 75-MHz@3.3-V, and a 8,192-point FFT can be computed m $762.7-{\mu}s$, thus the cores satisfy the specifications of wireless LAN, DMB, and DVB systems.

• Journal of the Korea Computer Graphics Society
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• v.8 no.1
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• pp.13-20
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• 2002

Recently, there is a great demand for artificial teeth prostheses made of the materials which are sintered at $1500^{\circ}C$ such as zirconia ceramic. Since degree of strength of the materials is very high, however, it is very difficult for technicians to manually fabricate the prostheses for these ceramics. So the prostheses have been fabricated by using CNC(computer numerical control) machines. In doing them by using CNC, it is very important that the prostheses satisfying dentists's requirements are accurately modeled into 3D objects. In this paper, we propose an effective method for modeling single cores such as single caps and Conus cores, which are the main those of artificial teeth prostheses. And we also present the visual examples of 3D models for these single cores modeled by the proposed methods. In special, the method has used Minkowski sum and ZMap for modeling the single cores.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.1-10
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• 2014

This paper proposes a scheduling scheme that enhances power consumption efficiency of periodic real-time tasks using DVFS and power-shut-down mechanisms while meeting their deadlines on multicore processors. The proposed scheme is suitable for dependent multicore processors in which processing cores have an identical speed at an instant, and resolves the load unbalance of processing cores by exploiting parallel processing because the load unbalance causes inefficient power consumption in previous methods. Also the scheme activates a part of processing cores and turns off the power of unused cores. The number of activated processing cores is determined through mathematical analysis. Evaluation experiments show that the proposed scheme saves up to 77% power consumption of the previous method.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.1129-1133
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• 2015

Background: The tissue microarray (TMA) is widely accepted as a fast and cost-effective research tool for in situ tissue analysis in modern pathology. However, the current automated and manual TMA techniques have some drawbacks restricting their productivity. Our study aimed to introduce an improved manual tissue miniarray (TmA) technique that is simple and readily applicable to a broad range of tissue samples. Materials and Methods: In this study, a conventional TV/radio telescopic antenna was used to punch tissue cores manually from donor paraffin embedded tissue blocks which were pre-incubated at $40^{\circ}C$. The cores were manually transferred, organized and attached to a standard block mould, and filled with liquid paraffin to construct TmA blocks without any use of recipient paraffin blocks. Results: By using a conventional TV/radio antenna, it was possible to construct TmA paraffin blocks with variable formats of array size and number ($2-mm{\times}42$, $2.5-mm{\times}30$, $3-mm{\times}24$, $4-mm{\times}20$ and $5-mm{\times}12$ cores). Up to $2-mm{\times}84$ cores could be mounted and stained on a standard microscopic slide by cutting two sections from two different blocks and mounting them beside each other. The technique was simple and caused minimal damage to the donor blocks. H&E and immunostained slides showed well-defined tissue morphology and array configuration. Conclusions: This technique is easy to reproduce, quick, inexpensive and creates uniform blocks with abundant tissues without specialized equipment. It was found to improve the stability of the cores within the paraffin block and facilitated no losses during cutting and immunostaining.