Comparisons of Production Costs of Japonica Rice Between China and Korea

( Wei Guang Pan ),( Chung Gil Chung ) 한국농촌경제연구원 2004 Journal of Rural Development Vol.27 No.2

In order to compare the comparative advantage of japonica between China and Korea, the study analyzes the production cost. After comparing the cost and its structure, it is found that the production of Japonica in China has more comparative advantage obviously. But the increasing rate is much higher than that of Korea in recent 10 years. In the long term, the gap between two countries will become smaller, while the inferior advantage of Korea can`t be changed during short-mid term. Some measures should be adopted to develop the competitiveness of japonica in Korea, such as, adjusting agricultural structure, enlarging the land scale and making quality differentiation.

Numerical Analysis and Application on the Parameters Optimization of Open-pit Deep-Hole Bench Loose Blasting

Guang-tao Li,Deng-pan Qiao,Hong-sheng Sun,Li-hua He 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.12

In order to improve the production efficiency of mine and ensure production safety and aiming at the unsatisfying blasting effects and uneven rock fragments existing in the exploitation blasting and construction process in Manjiazhai stope of Hualian Zinc and Indium Stock company, this paper analyzes and optimizes loosening blasting parameters of Open-pit deep-hole benches based on the blasting mechanism and engineering practical experience of wide hole distance and small resistance lines. Utilizing the numerical simulation of finite element software with ANSYS/LS-DYNA various schemes, analysis validations on the blasting stress field under different parameters are conducted. The simulation results show that: When the holes and rows spacing are 15×9, 16×9, 17×8, the effective stress of discrete cells between blast holes is bigger than the dynamic tensile strength that rocks can be broken. The site experimental investigation is conducted. The blasting effect assessment shows that the control rates of the big size rocks when the holes and rows spacing are 16×9 is 1.904% lower than those when those are 15×9, and 1.079% lower than those are 17×8. And the shovel mucking efficiency and composite economic results are better than that of the other two groups of parameters and confirmed the best blasting parameter design.

Fifth Generation Communication Performance of Poly(ether ketone ketone)/Modified Montmorillonite Substrate

Guang Kui Zhou,Xiao Dong Zhi,Deng Ming Pan,Tim Hsu,Jen-taut Yeh 한국고분자학회 2022 Macromolecular Research Vol.30 No.2

Quaternary ammonium salt modified montmorillonite (QASMMT) nanoplatelets were well dispersed in poly(ether ketone ketone) (PEKK) polymers to make pleasing fifth generation (5G) substrates. Substantially smaller dielectric properties and linear thermal expansion coefficient (LCTE) were found for each PEKKa xQASMMTy film series filled with small and appropriate QASMMT loadings. The dielectric constant (εr) and dielectric loss (tan δ) values acquired for each PEKKa xQASMMTy film series reduced to a lowest value as QASMMT loadings approached 3wt%. Satisfactory εr (2.59, 2.71, and 2.80 at 1 MHz), tan δ (0.0032, 0.0038, and 0.0042 at 1 MHz) and LCTE (~36.8×10-6/℃, 38.8×10-6/℃ and 40.5×10-6/℃) for 5G communication were acquired for PEKKa 97QASMMT3 films filled with only 3wt% optimum loading of QASMMT nano-platelets. In the meantime, the onset degradation temperatures acquired for each PEKKa xQASMMTy film series increased substantially with increasing QASMMT loadings. All free volume properties, such as, the radius of the free-volume-cavity or free-volume-cavity numbers per unit volume evaluated for every PEKKa xQASMMTy film sequence enlarged to a largest value, as QASMMT loadings approached an appropriate value of 3wt%. Substantial smaller εr and tan δ were acquired for PEKKa and PEKKa xQASMMTy with larger free volume properties. Possible reasons accounting for these substantially diminished dielectric and LCTE properties of PEKKa xQASMMTy films are proposed.

Evolution of the Mir-155 Family and Possible Targets in Cancers and the Immune System

Xie, Guang-Bing,Liu, Wei-Jia,Pan, Zhi-Jun,Cheng, Tian-Yin,Luo, Chao Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

The mir-155 family is not only involved in a diversity of cancers, but also as a regulator of the immune system. However, the evolutionary history of this family is still unclear. The present study indicates that mir-155 evolved independently with lineage-specific gain of miRNAs. In addition, arm switching has occurred in the mir-155 family, and alternative splicing could produce two different lengths of ancestral sequences, implying the alternative splicing can also drive evolution for intragenic miRNAs. Here we screened validated target genes and immunity-related proteins, followed by analyzation of the mir-155 family function by high-throughput methods like the gene ontology (GO) and Kyoto Eneyclopedin of Genes and Genemes (KEGG) pathway enrichment analysis. The high-throughput analysis showed that the CCND1 and EGFR genes were outstanding in being significantly enriched, and the target genes cebpb and VCAM1 and the protein SMAD2 were also vital in mir-155-related immune reponse activities. Therefore, we conclude that the mir-155 family is highly conserved in evolution, and CCND1 and EGFR genes might be potential targets of mir-155 with regard to progress of cancers, while the cebpb and VCAM1 genes and the protein SMAD2 might be key factors in the mir-155 regulated immune activities.

Icefex: Protocol Format Extraction from IL-based Concolic Execution

( Fan Pan ),( Li-fa Wu ),( Zheng Hong ),( Hua-bo Li ),( Hai-guang Lai ),( Chen-hui Zheng ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.3

Protocol reverse engineering is useful for many security applications, including intelligent fuzzing, intrusion detection and fingerprint generation. Since manual reverse engineering is a time-consuming and tedious process, a number of automatic techniques have been proposed. However, the accuracy of these techniques is limited due to the complexity of binary instructions, and the derived formats have missed constraints that are critical for security applications. In this paper, we propose a new approach for protocol format extraction. Our approach reasons about only the evaluation behavior of a program on the input message from concolic execution, and enables field identification and constraint inference with high accuracy. Moreover, it performs binary analysis with low complexity by reducing modern instruction sets to BIL, a small, well-specified and architecture-independent language. We have implemented our approach into a system called Icefex and evaluated it over real-world implementations of DNS, eDonkey, FTP, HTTP and McAfee ePO protocols. Experimental results show that our approach is more accurate and effective at extracting protocol formats than other approaches.

Numerical analysis of unsteady hydrodynamic performance of pump-jet propulsor in oblique flow

Qiu, Chengcheng,Pan, Guang,Huang, Qiaogao,Shi, Yao The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

In this study, the SST k - ω turbulence model and the sliding mesh technology based on RANS method have been adopted to simulate the exciting force and hydrodynamic of a pump-jet propulsor in different oblique inflow angle (0°, 10°, 20°, 30°) and different advance ratio (J = 0.95, J = 1.18, J = 1.58).The fully structured grid and full channel model have been adopted to improved computational accuracy. The classical skewed marine propeller E779A with different advance ratio was carried out to verify the accuracy of the numerical simulation method. The grid independence was verified. The time-domain data of pump-jet propulsor exciting force including bearing force and fluctuating pressure in different working conditions was monitored, and then which was converted to frequency domain data by fast Fourier transform (FFT). The variation laws of bearing force and fluctuating pressure in different advance ratio and different oblique flow angle has been presented. The influence of the peak of pulsation pressure in different oblique flow angle and different advance ratio has been presented. The results show that the exciting force increases with the increase of the advance ratio, the closer which is to the rotor domain and the closer to the blades tip, the greater the variation of the pulsating pressure. At the same time, the exciting force decrease with the oblique flow angle increases. And the vertical and transverse forces will change more obviously, which is the main cause of the exciting force. In addition, the pressure distribution and the velocity distribution of rotor blades tip in different oblique flow angles has been investigated.

Numerical analysis of unsteady hydrodynamic performance of pump-jet propulsor in oblique flow

Qiu, Chengcheng,Pan, Guang,Huang, Qiaogao,Shi, Yao The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

In this study, the SST k - ω turbulence model and the sliding mesh technology based on RANS method have been adopted to simulate the exciting force and hydrodynamic of a pump-jet propulsor in different oblique inflow angle (0°, 10°, 20°, 30°) and different advance ratio (J = 0.95, J = 1.18, J = 1.58).The fully structured grid and full channel model have been adopted to improved computational accuracy. The classical skewed marine propeller E779A with different advance ratio was carried out to verify the accuracy of the numerical simulation method. The grid independence was verified. The time-domain data of pump-jet propulsor exciting force including bearing force and fluctuating pressure in different working conditions was monitored, and then which was converted to frequency domain data by fast Fourier transform (FFT). The variation laws of bearing force and fluctuating pressure in different advance ratio and different oblique flow angle has been presented. The influence of the peak of pulsation pressure in different oblique flow angle and different advance ratio has been presented. The results show that the exciting force increases with the increase of the advance ratio, the closer which is to the rotor domain and the closer to the blades tip, the greater the variation of the pulsating pressure. At the same time, the exciting force decrease with the oblique flow angle increases. And the vertical and transverse forces will change more obviously, which is the main cause of the exciting force. In addition, the pressure distribution and the velocity distribution of rotor blades tip in different oblique flow angles has been investigated.

Numerical simulation of tip clearance impact on a pumpjet propulsor

Lu, Lin,Pan, Guang,Wei, Jing,Pan, Yipeng The Society of Naval Architects of Korea 2016 International Journal of Naval Architecture and Oc Vol.8 No.3

Numerical simulation based on the Reynolds Averaged Naviere-Stokes (RANS) Computational Fluid Dynamics (CFD) method had been carried out with the commercial code ANSYS CFX. The structured grid and SST $k-{\omega}$ turbulence model had been adopted. The impact of non-condensable gas (NCG) on cavitation performance had been introduced into the Schnerr and Sauer cavitation model. The numerical investigation of cavitating flow of marine propeller E779A was carried out with different advance ratios and cavitation numbers to verify the numerical simulation method. Tip clearance effects on the performance of pumpjet propulsor had been investigated. Results showed that the structure and characteristics of the tip leakage vortex and the efficiency of the propulsor dropped more sharply with the increase of the tip clearance size. Furthermore, the numerical simulation of tip clearance cavitation of pumpjet propulsor had been presented with different rotational speed and tip clearance size. The mechanism of tip clearance cavitation causing a further loss of the efficiency had been studied. The influence of rotational speed and tip clearance size on tip clearance cavitation had been investigated.

Numerical simulation of tip clearance impact on a pumpjet propulsor

Lin Lu,Guang Pan,Jing Wei,Yipeng Pan 대한조선학회 2016 International Journal of Naval Architecture and Oc Vol.8 No.3

Numerical simulation based on the Reynolds Averaged NaviereStokes (RANS) Computational Fluid Dynamics (CFD) method had been carried out with the commercial code ANSYS CFX. The structured grid and SST keu turbulence model had been adopted. The impact of noncondensable gas (NCG) on cavitation performance had been introduced into the Schnerr and Sauer cavitation model. The numerical investigation of cavitating flow of marine propeller E779A was carried out with different advance ratios and cavitation numbers to verify the numerical simulation method. Tip clearance effects on the performance of pumpjet propulsor had been investigated. Results showed that the structure and characteristics of the tip leakage vortex and the efficiency of the propulsor dropped more sharply with the increase of the tip clearance size. Furthermore, the numerical simulation of tip clearance cavitation of pumpjet propulsor had been presented with different rotational speed and tip clearance size. The mechanism of tip clearance cavitation causing a further loss of the efficiency had been studied. The influence of rotational speed and tip clearance size on tip clearance cavitation had been investigated.

Study on stability of self-synchronous far-resonant vibrating system of two eccentric rotors considering material impact

Yongjun Hou,Guang Xiong,Pan Fang,Yuwen Wang,Mingjun Du 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.8

The self-synchronizing far-resonant vibrating system of two eccentric rotors is widely used in petroleum, mining and food industries, and its motion stability is affected by material impact. However, the synchronous characteristics and stability of this kind of the system are studied rarely. Based on the background, a simplified mechanical model of the selfsynchronous vibrating system driven by two eccentric rotors considering material impact is proposed. Firstly, the differential equations of motion about the system in non-collision and collision phase are established by using Lagrange equation and the theorem of momentum. Then, the section of Poincare maps and linearization matrix at the fixed point are solved. Finally, the dynamic behavior of material and system is analyzed, and then the change characteristics of the phase difference of the two eccentric rotors are revealed by numerical simulation. It can be concluded that the motion forms of the system and the rules of abrupt change about the phase difference evolve from periodic variation into chaotic state with the mass ratio of material to vibrating body increasing.