Study on synchronization characteristics for self-synchronous vibration system with dual-frequency and dual-motor excitation

Min Zou,Pan Fang,Huan Peng,Duyu Hou,Mingjun Du,Yongjun Hou 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.3

In petroleum drilling engineering, drilling shakers are critical devices for cleansing solid particles and recycling drilling fluid. For the problem that the vibration screen with a single frequency usually results in flurry overflow due to the blocking of screen mesh, a selfsynchronous vibratory system with dual-frequency and dual-motor excitation is proposed. But it is not clear about the synchronization mechanism and dynamic characteristics of the system, which causes a lack of theoretical description for the source of synchronization phenomenon. Hence, this paper explores the synchronization mechanism and dynamic characteristics around the proposed system above. First, vibration and stability theory are employed to master the dynamic characteristics of the system, and the dynamic model is established by Lagrange equation. Then, displacement responses of the system are obtained by dimensionless formulas. Synchronous condition and synchronous stability between the unbalanced rotors are derived with small parameter method and Poincare method. Finally, some computer simulations are implemented to further verify the correctness of the theoretical analysis. The research result shows that the synchronous ability between the two unbalanced rotors actuated by dual-frequency excitation is related to the distance from the rotating center of the motor to the centroid of supporting body, and the greater the distance value, the better the synchronization of the vibrating system. This study will promote the recycle technology development of drilling fluid and settlement of the common scientific issues in vibrating synchronization.

Auto-hydrolysis in Combination with Mechanical Refining

Hou-min Chang,Hasan Jameel,Richard B. Phillips,Sunkyu Park 한국펄프·종이공학회 2016 한국펄프·종이공학회 학술발표논문집 Vol.2016 No.10

Exploring Information Warfare Strategies during the Russia–Ukraine War on Twitter

Shu–Min Hou,Wen-Cheng Fu,Shao–Yi Lai 한국국방연구원 2023 The Korean Journal of Defense Analysis Vol.35 No.1

Twitter, one of the mainstream social media platforms, has played a significant role in strategic communication and public diplomacy. Using tweets during the 2022 Russia–Ukraine war period as a case study, the researchers aim to build a pipeline that automatically detects information manipulation. Artificial intelligence and machine learning technology are adopted to target certain coordinated groups of people, and how they manipulate online public opinion internationally via social media platforms by retweeting identical tweets between members within the groups and even with their own tweets. With the large number of tweets posted and retweeted by the coordinated groups, their intended content will appear in the news feeds of normal users. This study maps an approach to future warfare that social media is becoming a vital part of information warfare to influence the results of conflict and regional relationships. The researchers argue that the government should consider taking countermeasures: 1) Set up legislation regarding media platforms and cooperate with social media companies to monitor manipulating behaviors. 2) Establish a model to orchestrate inter-agency defensive strategies. 3) Increase people’s media literacy to allow them to be aware of manipulative and collaborative behavior and decrease their likeliness to spread fake/manipulated information online unintentionally. Also, similar research can be adapted to different regional conflicts.

[Oral Session 4] THE EFFECT OF FILLERS ON THE DEINKING OF PHOTOCOPIED PAPER

Qing-min Chen,Hou-min Chang 한국펄프·종이공학회 1999 한국펄프종이학회 기타 간행물 Vol.- No.-

Model experiments were conducted to investigate the effect of different fillers on the removal of toner ink. Combinations of different papers (commercial photocopy paper and filler-free paper), fillers (calcium carbonate, kaolin clay, and talc), and chemicals (l-octadecanol, stearic acid, oleic acid, and TOFA) were studied. In the absence of fillers, l-octadecanol, oleic acid, tall oil fatty acid (a mixture of unsaturated fatty acids consisting mainly of oleic and linoleic acids-TOFA) and stearic acid were found to be effective in detachment and agglomeration of toner ink. Furthermore, pH had little effect on toner detachment and agglomeration, indicating both protonated fatty acids and their anions are equally effective. In the presence of either kaolin clay or talc, all these agglomerating agents are equally effective, although a slightly higher dosage (1 % for clay and 2% for talc as compared with control) is required, presumably due to the adsorption of chemical by the filler. Calcium carbonate filler, on the other hand, has a significant and adverse effect on the fatty acids used but has little effect on l-octadecanol with the exception of possible adsorption. While stearic acid is not effective, a much higher level of oleic acid or TOFA is needed when calcium carbonate fillers are present as compared to the fillers case. Fatty acids react with calcium carbonate to form calcium salts. The availability of fatty acid anion for toner detachment and agglomeration is determined by the solubility of calcium salt of a given fatty acid. Calcium oleate is 10 times more soluble in water than calcium stearate.

Antitumor Effects of Hyperthermic CO₂ Pneumoperitoneum on Human Gastric Cancer Cells

Zhou, Hou-Min,Feng, Bo,Zhao, Hong-Chao,Zheng, Min-Hua Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

Aim: To elucidate the effects of hyperthermic $CO_2$ pneumoperitoneum on human gastric AGS cells. Methods: Based on a newly devised in vitro study model, we evaluated the anti-cancer effects of HT-$CO_2$ ($42-44^{\circ}C$ for 2-4h) on human gastric cancer cells, and also the corresponding mechanisms. Results: HT-$CO_2$ ($42-44^{\circ}C$ for 2-4h) severely inhibited cell proliferation as assessed by Cell Counting Kit-8 assay, while inducing apoptosis in a temperature- and time-dependent manner demonstrated by annexin-V/PI flow cytometry and morphological analysis (Hoechst/PI fluorescence). In addition, it was found that HT-$CO_2$ ($42-44^{\circ}C$ for 2-4h) promoted the up-regulation of Bax by western blotting. Significantly, it could also suppress gastric cancer cell invasion and metastasis by in vitro invasion and motility assay. Conclusion: In conclusion, HT-$CO_2$ had an efficacious cytotoxic effect on gastric cancer cells through Bax-induced mitochondrial apoptotic signaling. Our studies indicate that it may serve as a potential therapy for peritoneal carcinomatosis of gastric cancer. Further investigations in vivo using animal models are now urgently needed.

Magnetic Properties and Giant Magnetocaloric Effects on Gd-Ge-Si Alloy by Substitution of Sn

Seong-Gi Min,Ying De Zhang,Chul-Min Heo,Xueling Hou,Ying Li,Seong-Cho Yu,Kyu- Won Lee 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

열처리 가공조건에 따른 씀바귀 침출차의 생리활성

이가순(Ka-Soon Lee),김관후(Gwan-Hou Kim),김현호(Hyun-Ho Kim),김은수(Eun-Soo Kim),박혜민(Hae-Min Park),오만진(Man-Jin Oh) 한국식품영양과학회 2009 한국식품영양과학회지 Vol.38 No.4

씀바귀뿌리를 이용하여 침출차를 제조하고자 건조온도 및 처리조건을 달리하여 생리활성을 검토하였다. 각각의 씀바귀뿌리 침출차의 침출액에 대한 생리활성을 측정한 결과, 전자공여능은 증숙처리 후 열풍건조한 것이 98%로 가장 높았고 뒤이어 천일건조>열풍건조 후 볶음처리>열풍건조의 순으로 높았으며, 침출액의 SOD유사활성은 열풍건조 후 볶음 처리한 씀바귀뿌리 추출물에서 35.61±0.67%의 활성을 보였다. ACE저해활성은 천일건조한 것이 44.60%로 가장 저해활성이 가장 높았고, 증숙 처리 후 열풍건조한 처리구가 가장 낮아 28.89%의 저해활성을 보였고, tyrosinase 저해활성은 천일건조한 것이 44.61%로 가장 높았고 열풍건조>열풍건조 후 볶음처리>증숙처리 후 열풍건조의 순으로 저해활성을 나타내었으며, 아질산염 소거능은 pH가 낮을수록 효과가 있었으며, 특히 열풍건조 후 볶음처리를 한 씀바귀뿌리 침출차의 침출액이 모든 pH 구간에서 가장 효과적인 것을 볼 수 있었다. This study was carried out to investigate physiological functionalities of tea prepared by various thermal processing methods from Ixeris dentata root in order to elevate utilization of Ixeris dentata root as food. These methods included natural drying (ND), hot-air drying (HAD, 75℃), hot-air drying after steam (HADS, steaming at 95℃ for 30 min) and roasting after hot-air drying (RHAD, roasting at 140℃ for 2~3 min). Physiological functionalities of tea prepared by ND, HAD, HADS, and RHAD were measured as hot-water extracts and each tea was extracted by 100 ㎖ water on 1 g dried Ixeris dentata root powder. Electron donating abilities were the highest in HADS treatment at 98%. SOD-like activities were the highest in RHAD at 35.61%. Both ACE and tyrosinase inhibitory activities were the highest on ND treatment at 52.34% and 44.60%, respectively. Nitrite scavenging abilities of all treatment were the highest at pH 1.2 and the highest activity among them was on RHAD treatment at 50.5%.

Effects of screen size, viewing angle, and players’ immersion tendencies on game experience

Hou, Jinghui,Nam, Yujung,Peng, Wei,Lee, Kwan Min Elsevier 2012 Computers in Human Behavior Vol.28 No.2

<P><B>Highlights</B></P><P>► We examine the effect of screen size and users’ immersion tendencies. ► Large screen size leads to higher level of presence and better gaming experiences. ► Users’ immersion tendencies have a moderating effect on presence experiences.</P> <P><B>Abstract</B></P><P>This study investigated the effects of viewing angle manipulated through screen size and the moderating role of players’ immersion tendencies on presence experience in the context of computer game playing. Thirty participants played a third-person computer game, <I>Tomb Raider 2</I>, in two screen size conditions: a 12.7-in. and an 81-in. display. ANCOVA analyses showed that playing in front of a large screen led to a more favorable impression on the game character, a more positive mood change, and significantly higher feelings of both physical and self-presence, confirming previous research. Our findings also revealed that individuals’ intrinsic immersion tendencies have a positive moderating effect on the sensation of physical and self-presence, above and beyond the influence of screen size. The results suggest that feeling of presence as well as overall game experience is determined by the interaction between technological factors and human influence.</P>

3',4',5',5,7-Pentamethoxyflavone Sensitizes Cisplatin-Resistant A549 Cells to Cisplatin by Inhibition of Nrf2 Pathway

Hou, Xiangyu,Bai, Xupeng,Gou, Xiaoli,Zeng, Hang,Xia, Chen,Zhuang, Wei,Chen, Xinmeng,Zhao, Zhongxiang,Huang, Min,Jin, Jing Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.5

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important redox-sensitive transcription factor that regulates the expression of several cytoprotective genes. More recently, genetic analyses of human tumors have indicated that Nrf2 may cause resistance to chemotherapy. In this study, we found that the expression levels of Nrf2 and its target genes GCLC, HO-1, NQO1 were significantly higher in cisplatin-resistant A549 (A549/CDDP) cells than those in A549 cells, and this resistance was partially reversed by Nrf2 siRNA. 3,4,5,5,7-Pentamethoxyflavone (PMF), a natural flavon extracted from Rutaceae plants, sensitized A549/CDDP to CDDP and substantially induced apoptosis compared with that of CDDP alone treated group, and this reversal effect decreased when Nrf2 was downregulated by siRNA. Mechanistically, PMF reduced Nrf2 expression leading to a reduction of Nrf2 downstream genes, and in contrast, this effect was decreased by blocking Nrf2 with siRNA. Taken together, these results demonstrated that PMF could be used as an effective adjuvant sensitizer to increase the efficacy of chemotherapeutic drugs by downregulating Nrf2 signaling pathway.

Continuous Trajectory Point Control Research of Six Degree of Freedom Mechanical Intelligent Arm Position

Min Wang,Zhixiang Hou 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.2

In view of the low pointing accuracy problem of the hanging wire weight control method adopted in current mechanical arm control, for the control of the mechanical arm, a mechanical intelligent arm position control method based on continuous trajectory point control is proposed to improve the control accuracy of mechanical intelligent arm. The kinematic behavior planning model of the mechanical arm in six degree of freedom motion space is constructed. The end-effect inverse kinematics decomposition method is used to obtain the vector set of mechanical arm joint rotation. The parametric self-tuning regulation is used to control parameters optimization. Continuous trajectory point control method is adopted to improve the accuracy of mechanical intelligent arm position change and achieve high-precision arm control. Simulation results show that six degree of freedom mechanical intelligent arm accuracy control has higher precision, minimized convergence error and higher robustness with this control method.